Introduction

For three decades, North Korea’s pursuit of a nuclear arsenal has been the predominant U.S. foreign policy concern on the Korean Peninsula, threatening both regional stability and the global nonproliferation regime. Although multiple countries have a major stake in the issue, the U.S. has been both the most important interlocutor in attempts to resolve it diplomatically and the leader in global efforts to pressure and isolate North Korea. Efforts to address North Korea’s nuclear weapons program through various combinations of diplomacy and pressure have at times slowed or temporarily halted Pyongyang’s progress, but have failed to roll it back or to fundamentally change the dynamics of conflict on the Peninsula.

As North Korea has dramatically accelerated the pace of progress in building its nuclear program in recent years, and as the Trump administration has alternately leveled threats of military action and engaged in high-profile summitry with Kim Jong-un, this issue has risen to the top of the U.S. foreign policy agenda. The current round of U.S. diplomatic engagement with North Korea may hold enormous consequences for the future of the Korean Peninsula, perhaps leading to the denouement of this long saga – or, despite the high stakes, perhaps simply to another round of all sides “muddling through” with no ultimate resolution in sight. The Trump administration has framed negotiations with North Korea in stark binary terms – either leading to North Korea’s denuclearization and prosperity, or to a more intensified confrontation and conflict – but few experts expect North Korea to give up its nuclear arsenal any time soon.

This Issue Brief will review the history of U.S. nuclear negotiations with North Korea, taking a close look at past efforts to realize the denuclearization of the Korean Peninsula. It will also examine the persistent questions and themes surrounding how the U.S. has approached the issue of negotiating with Pyongyang, and how foreign analysts have perceived the motivations behind North Korea’s nuclear program.

Assessing North Korea’s Goals

Over the decades, Pyongyang has been consistent in outlining what it wants from the United States, though the details have shifted from time to time. North Korea has repeatedly called for a peace treaty and normalized relations with Washington, and – above all – an end to what it calls the U.S. “hostile policy.” Typically, North Korean negotiators have used this term to describe what they see as a combination of:

• Economic sanctions or (in past years) the withholding of economic assistance;

• Criticism of the North Korean state and its institutions, particularly criticism of the country’s human rights record or insults directed at the ruling Kim family; and

• Military threats, particularly joint military exercises between the U.S. and South Korea and threats (spoken or implicit) of U.S. use of nuclear weapons in a conflict.

Many analysts, skeptical of North Korea’s willingness to disarm, have argued that North Korea seeks de facto recognition of its status and legitimacy as a nuclear-armed state, akin to other nuclear-armed states outside the Non-Proliferation Treaty such as Pakistan. Over the years, North Korea has expressed its support for “the denuclearization of the Korean Peninsula,” but this term may have a very different interpretation in Pyongyang than it does abroad. The “denuclearization of the Korean Peninsula,” as a North Korea official described it in 2013, means “totally remov[ing] the U.S. nuclear threat to the DPRK,” with eventual North Korean nuclear disarmament coming in the context of global efforts “to achieve denuclearization of the world.”1

Additionally, many analysts assume that the withdrawal of U.S. troops from the Korean Peninsula is a key North Korean objective, reflecting the country’s long-standing rhetoric and propaganda. However, at key points in diplomatic negotiations – the first high-level U.S.-DPRK talks in 1992, the 2000 inter-Korean summit, and as renewed engagement with South Korea and the U.S. began in 2018 – North Korea’s leaders privately indicated their willingness to accept a long-term U.S. military presence on the Peninsula.

Although much of the U.S. media discourse about North Korea portrays the country’s leadership and its pursuit of nuclear arms as bizarre and illogical, the vast majority of specialists see the North Korean regime as rational and calculating (if ruthless) in the pursuit of self-preservation. In assessing the motivations behind North Korea’s nuclear program and the history of its diplomatic engagement with the United States, however, expert analysis diverges sharply and could be broadly categorized into three general frames:

North Korea as an Isolated State: One line of analysis interprets the motivations behind North Korea’s nuclear program and many of its adversarial actions and negotiating tactics as springing from a deep sense of insecurity and nationalist pride, amidst a world of unreliable allies and of perceived antagonists in Seoul, Tokyo, and Washington who seek the regime’s dissolution. This combination of insecurity, nationalism, and commitment to continued rule by the Kim family drives North Korea’s domestic political system, as well as its approach to foreign relations.

According to this view, North Korea has long sought to normalize relations with the U.S. in order to guarantee its security and to avoid dependence on China as a patron. In its early years, North Korea’s nuclear program was primarily useful as a bargaining chip for Pyongyang to achieve this objective, but missed opportunities and wrongheaded actions by Washington – particularly the decision to jettison the Agreed Framework in 2002 – seem to have convinced North Korea to pursue a more robust nuclear deterrent. Subsequent U.S. policies based on sanctions and shows of military force have been misguided, deepening Pyongyang’s sense of external threat while triggering North Korea’s proclivity to escalate in response to pressure. However, Kim Jong Un’s apparent commitment to economic development and modernization, paired with his high-level outreach to South Korea, China, and the U.S., may have opened the door for a meaningful new opportunity for negotiations.2

North Korea as a Hyper-Realist State: An alternative hypothesis posits that North Korea’s leaders view military power – not alliances or embeddedness in the international order – as the only meaningful guarantee of security, and nuclear weapons as the ultimate currency of power. In past nuclear negotiations, Pyongyang may have made tactical concessions to ward off pressure, gain temporary benefits, and divide its adversaries; however, North Korea has ultimately relied on strategic deception to gradually build up its nuclear capabilities. The North Korean regime sees its nuclear arsenal as a deterrent against foreign military intervention, and is determined to avoid the kind of example set by Libya, where Muammar Gaddafi was overthrown and killed in a U.S.-supported uprising eight years after surrendering his country’s nascent nuclear program.

Nuclear deterrence, combined with a strong tolerance for risk, also provides Pyongyang with the freedom of action to pursue its interests as it sees fit and to violate international norms of state behavior with relative impunity. Additionally, the country’s nuclear program and the sense of external threat it has engendered serve as sources of regime legitimacy and national cohesion; North Korea’s leaders recognize that economic openness and tranquil relations with neighbors would ultimately pose a major threat to their survival. Viewed from this perspective, nuclear negotiations with North Korea may act as a form of crisis management, but will not lead to disarmament absent fundamental changes in the country’s sociopolitical institutions.3

North Korea as a Revisionist State: This view argues that North Korea has pursued a nuclear arsenal primarily for coercive purposes rather than for deterrence, and seeks to decouple the U.S. from its alliance with Seoul and to ultimately subjugate South Korea. Many analysts have dismissed North Korea’s post-Cold War rhetoric about unification as hollow propaganda, given the vast economic disparities between North and South Korea and the seeming-impossibility of North Korea absorbing the open, democratic society south of the DMZ. In contrast, proponents of this hypothesis argue that Pyongyang is driven by a deep ideological commitment to unification under its terms. Kim Jong Un’s rhetoric emphasizing “final victory” demonstrates North Korea’s intention to unify the Peninsula under its aegis, while the country’s development of nuclear-armed missiles would provide it with the means to coerce or defeat a conventionally-armed South Korea and deter a U.S. intervention. Advocates of this perspective have largely dismissed past efforts to negotiate with North Korea as appeasement, painting Pyongyang as a ruthless manipulator that has consistently outmaneuvered feckless U.S. diplomats.4

The Questions of U.S. Diplomatic Strategy

With these different general perspectives as rough baselines for interpreting the motivations behind North Korea’s behavior and its nuclear program, over nearly three decades of on-and-off nuclear negotiations have consistently produced some of the same themes and strategic questions about the direction U.S. policy should take.

The first question has been whether Washington’s fundamental approach of prioritizing efforts to address North Korea’s nuclear program above other issues has been correct. Proponents of engagement strategies have argued that North Korea’s sense of insecurity has driven it to develop nuclear weapons, and that providing Pyongyang with security assurances and opportunities to reform and integrate into the international system will ultimately break the cycle of tensions and threats on the Korean Peninsula.5 Some human rights advocates have made the case that diplomacy aimed at the nuclear program has led the U.S. and other countries to deprioritize efforts to address systematic human rights abuses in the country, and have helped legitimize a brutal and untrustworthy regime.6

Many analysts – echoing what appears to be a consensus within the U.S. intelligence community – believe that the North Korean regime will never consent to relinquishing its nuclear weapons, calling into question the viability of the goal of complete denuclearization as pursued by the U.S. and enshrined by multiple UN Security Council resolutions.7 To hardline critics, the history shows that negotiating with North Korea is of little or no value and that U.S. policy should be aimed at bringing about regime collapse or capitulation.8 However, more moderate voices argue that negotiating with North Korea has merit even if it doesn’t lead to denuclearization, as diplomacy could help to slow or halt technical advances in North Korea’s nuclear arsenal, and reduce the prospects of conflict or provocations.9

Nonetheless, each U.S. administration for the past thirty years has maintained the stated goal of achieving the denuclearization of North Korea through diplomatic means and has tried to varying degrees to engage in talks with Pyongyang over its nuclear program. The potential human cost of a full-scale military conflict with North Korea – where projections of casualties range in the hundreds of thousands, or in the millions if nuclear weapons are involved – has cast a heavy shadow over the option of using military force to destroy the country’s nuclear infrastructure. Policies aimed at regime change through non-military means would have to accept the risks of instigating the collapse of a nuclear-armed state, and to reckon with the difficult fact – as the famine of the 1990s demonstrated – that the North Korean regime is willing to impose a high level of pain on its population to stay in power. Recognition or de facto acceptance of North Korea’s nuclear-armed status, on the other hand, would represent an embarrassing retreat from decades of U.S. policy and a blow to the global nonproliferation regime, without any guarantee that it would lead to a more peaceful or stable Korean Peninsula.

Within the context of negotiations, a consistent challenge has been coordinating the U.S. position on North Korea policy with that of other key regional actors. Although China has opposed North Korea’s nuclear buildup and voted in favor of multiple UN sanctions resolutions, Beijing has generally prioritized stability on the Korean Peninsula over denuclearization, and – particularly before 2017 – did little to enforce sanctions. South Korea’s approach to North Korea has fluctuated as pro-engagement progressives and more hawkish conservatives have alternated in power, and the policy preferences of Seoul and Washington have been out of sync at several crucial periods. The direction of Japanese policy toward North Korea has generally been more consistent with that of the U.S., but Tokyo’s focus on addressing the decades-old abduction of its nationals by North Korea has sometimes conflicted with Washington’s prioritization of nuclear matters. Russia has had less of a direct stake in the politics of the Korean Peninsula than other parties, but has sought to keep a seat at the table and has threatened at times to play a spoiler role in international efforts to pressure North Korea over its nuclear program. Tied to the management of these relationships has been the question of whether nuclear negotiations with North Korea should be a bilateral U.S.-DPRK affair, or a multilateral one.

Another major consistent question of U.S. diplomatic strategy has been identifying the right combination of pressure and inducements to get Pyongyang to the table on acceptable terms, and to bargain for nuclear concessions once talks have begun.10 A related issue has been how each side would sequence their respective actions to get to the end goal of a denuclearized and peaceful Korean Peninsula, given their mutual mistrust and the long list of measures (some reversible, some not) necessary to achieve this goal. The dynamics of phased negotiations, coupled with a tendency for the two sides to agree to vaguely-worded joint statements rather than finely-detailed agreements, have repeatedly provided the U.S. and North Korea the opportunity to accuse the other – rightly or wrongly, as the case may be – of failing to live up to their obligations.

The First North Korean Nuclear Crisis                      

North Korea’s interest in nuclear technology began decades before the country’s nuclear program rose to the top of the U.S. foreign policy agenda in the 1990s. North Korea’s early nuclear activities in the 1950s and 60s were focused on building a corps of trained nuclear experts and developing the foundations of a national nuclear infrastructure with assistance from abroad, primarily from the Soviet Union. By the 1970s, North Korean leader Kim Il Sung began to lay the groundwork for the country’s indigenous development of a nuclear weapons program, and in 1979 North Korea began construction of a 5 MWe experimental nuclear reactor at Yongbyon – a Magnox-type reactor that could operate on natural uranium and produce spent fuel for reprocessing into weapons-grade plutonium.

In 1985, as North Korea neared completion of the 5 MWe reactor, it signed the Non-Proliferation Treaty under Soviet (and indirectly, American) pressure. However, after acceding to the NPT Pyongyang did not follow up by signing a requisite nuclear safeguards agreement with the International Atomic Energy Agency. Instead, North Korea linked its willingness to submit to IAEA inspections to the withdrawal of U.S. nuclear weapons from South Korea, where they had been deployed since 1958. By the late 1980s, North Korea began operations at a radiochemical laboratory capable of reprocessing spent nuclear fuel to extract plutonium for nuclear weapons, and started construction of two larger gas-graphite reactors.

The end of the Cold War led to a swift deterioration of North Korea’s strategic position, with Pyongyang’s traditional allies in Moscow and Beijing establishing diplomatic relations with Seoul and ending the subsidized trade on which North Korea had come to depend. The sudden loss of fuel subsidies from the Soviet Union, coupled with a legacy of economic mismanagement, led to a massive economic contraction and the onset of famine by the mid-1990s. As North Korea sought a path ought of international isolation and economic collapse, its nuclear program took on renewed importance, not only as a potential military deterrent but also as a major source of leverage in Pyongyang’s dealings with its traditional adversaries in Washington, Seoul, and Tokyo.11

Increasingly concerned about North Korea’s nuclear ambitions, the U.S. quietly began to open up diplomatic communication channels with Pyongyang, breaking with decades of minimal direct contact between the two nations.12 Concurrently, South Korea pursued a policy of Nordpolitik aimed at rapprochement with the North and its traditional allies. In 1991, the U.S. announced the withdrawal of its nuclear weapons from South Korea, reflecting both a retrenchment of its global nuclear posture and an effort to persuade North Korea to accept international inspections of its nuclear sites. Separately, the U.S. and South Korea announced the cancellation of the annual “Team Spirit” joint military exercises, which Pyongyang had vociferously opposed for years.

These two actions met North Korea’s stated requirements for allowing IAEA inspections of its nuclear facilities and opened the door to negotiations. In December 1991, the two Koreas signed a “Basic Agreement” pledging the two sides to reconciliation and cooperation, followed shortly by a Joint Declaration on the Denuclearization of the Korean Peninsula, under which North and South agreed not to “test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons.” North and South Korea also pledged not to possess nuclear reprocessing or uranium enrichment facilities. While the two Koreas were negotiating this agreement, the U.S. and North Korea convened a high-level diplomatic meeting in New York, leading to North Korea’s decision to permit IAEA inspections of its nuclear facilities. The bilateral inspection mechanism envisioned by the inter-Korean Joint Declaration did not get off the ground, marking the start of a pattern of Pyongyang insisting that Washington be its main interlocutor on nuclear matters. However, North Korea soon submitted a nuclear material declaration to the IAEA and allowed inspections of certain agreed-upon sites.

As IAEA inspectors scrutinized these declared nuclear activities, they detected discrepancies suggesting that from 1989 to 1991 North Korea may have covertly produced enough plutonium to build one or two nuclear weapons. When the IAEA requested the “special inspection” of suspect facilities in early 1993, North Korea – surprised by the scope of the organization’s forensic capabilities and the unprecedented nature of the inspection request – refused the request and announced its intention to withdraw from the NPT.13 This led to further bilateral talks with the U.S., and the adoption of a joint statement in which the two countries pledged to support a nuclear-free Korean Peninsula, respect one another’s sovereignty, and refrain from the use or threat of force; as part of this agreement, North Korea also “suspended” its NPT withdrawal. Subsequent IAEA efforts to inspect the suspected reprocessing facility stalled, however, and North Korea’s removal of spent fuel rods from its 5 MWe reactor for possible reprocessing to extract plutonium took the crisis to an apex. Facing the prospect of a brazen nuclear breakout, U.S. policymakers began considering pursuing tough international sanctions or a military response – an option that the Clinton administration recognized could lead to a devastating conflict on the Peninsula. 

The Agreed Framework

With official negotiations at a standstill, former President Jimmy Carter traveled to Pyongyang in June 1994 in an unofficial capacity, facilitating a return to dialogue and outlining the terms of a nuclear agreement during a meeting with Kim Il Sung. Bilateral U.S. talks with North Korea continued despite Kim Il Sung’s death in July, with the two sides signing the Agreed Framework in October 1994. Under this agreement, North Korea agreed to freeze operations at its nuclear facilities in Yongbyon and halt the construction of its new planned reactors. In return, the U.S. agreed to create a consortium (the Korean Peninsula Energy Development Organization, or KEDO) to provide heavy fuel oil shipments and begin building two proliferation-resistant light-water nuclear reactors (LWRs) in North Korea. Before construction of these LWRs was complete, however, North Korea would be obliged to take an additional set of steps including dismantling its old reactors, coming into full compliance with its IAEA obligations, and shipping its plutonium-laden spent fuel rods out of the country. Title II of the Agreed Framework also laid out steps to achieve “full normalization of political and economic relations” between the U.S. and DPRK.14

The Agreed Framework alleviated the immediate sense of crisis surrounding North Korea’s nuclear program. The agreement froze nuclear activities at Yongbyon and led to the de facto abandonment of North Korea’s two other nascent nuclear reactors. (The CIA had estimated that, upon completion, these reactors would be capable of generating enough plutonium to produce dozens of nuclear weapons every year.)15 In the years after the U.S. and North Korea signed the agreement, the two sides made some progress in working-level bilateral talks on implementation details and on confidence building measures such as cooperation to recover the remains of Korean War-era U.S. service members from North Korea. With North Korea’s economic collapse leading to devastating famine by the mid-1990s, the U.S. also emerged as the largest donor for humanitarian assistance to the country.

However, U.S. relations with North Korea remained highly uneasy during this period, and implementation of the Agreed Framework was often fraught with uncertainty. The U.S. Congress, skeptical of the agreement’s merits, was reluctant to fund the heavy fuel oil shipments promised by it, leading to delays in delivery. Construction of the LWRs in North Korea also proceeded slowly, due to the unique and complex nature of the project.16 Additionally, the U.S. and North Korea made little progress toward normalizing diplomatic or economic relations, and did not establish interests sections in each other’s capitals as outlined by the Agreed Framework.17 Four Party Talks aimed at negotiating a peace treaty to replace the 1953 Armistice Agreement, held between the U.S., China, and the two Koreas from 1997-1999, deadlocked without an agreement.

Military tensions on the Korean Peninsula also continued in the years after the Agreed Framework was signed. In December 1994, North Korea shot down a U.S. helicopter that had strayed into North Korean airspace; in 1996, a North Korean submarine ran aground in South Korean territory during a reconnaissance mission, leading to a massive manhunt; and in August 1998 North Korea attempted to launch a satellite into orbit using a Taepodong-1 rocket, marking Pyongyang’s first use of long-range missile technology. Additionally, by 1998 U.S. intelligence agencies began picking up indications of a nascent North Korean effort to acquire uranium enrichment technology, which would potentially provide Pyongyang with an alternative path to the bomb.

Amid growing concerns over the North Korean missile program, the prospect of undeclared nuclear activities, and the uneven implementation of the Agreed Framework, the Clinton administration appointed former Secretary of Defense William Perry to conduct a comprehensive review of U.S. policy toward North Korea in late 1998. The resulting report called for an enhanced diplomatic effort to address North Korea’s nuclear weapons and ballistic missile-related programs, backed by a second track of containment should talks fail.18

As the “Perry Process” between the U.S. and North Korea commenced, Washington and Pyongyang began an intensified process of official engagement. Although the Clinton administration did not confront Pyongyang over the uranium enrichment issue – given a lack of actionable evidence and the apparently limited scale of Pyongyang’s activities at this time – it focused on gaining access to an underground military site at Kumchang-ri, where the U.S. Defense Intelligence Agency believed North Korea was constructing a covert nuclear facility. In March 1999, a State Department team reached an agreement to visit this site, concluding that operations there did not violate the Agreed Framework.19 Several months later, during negotiations on its ballistic missile program, Pyongyang agreed to a missile test moratorium in exchange for Washington partially lifting economic sanctions.

The final months of the Clinton administration saw a burst of high-level diplomacy, as well as a warming of inter-Korean relations following the first inter-Korean summit in June 2000. In October 2000 a high-ranking North Korean official, Vice Marshal Jo Myong Rok, visited Washington, leading to a Joint Communique on efforts to improve U.S.-DPRK relations.20 Shortly thereafter, Secretary of State Madeleine Albright visited Pyongyang to meet with North Korean leader Kim Jong Il. Nonetheless, an envisioned follow-up visit by President Clinton to Pyongyang did not materialize, owing to ongoing disagreements over the final terms of a missile deal and a political crisis in Washington following that November’s disputed election.

The incoming George W. Bush administration had deep internal divisions about its policy toward North Korea and the wisdom of engaging in diplomacy with Pyongyang.21 Although implementation of the Agreed Framework continued as the Bush administration took office, missile talks with North Korea were suspended, and the new administration sent mixed signals about its willingness to negotiate with Pyongyang – an approach at odds with the engagement policies then being pursued by Seoul and (to a lesser extent) Tokyo. An internal policy review on North Korea, released in June 2001, called for a “bold approach” strategy addressing a comprehensive set of security, economic, and political issues; however, there was little immediate follow-up to begin implementing this strategy. The administration’s approach to foreign policy hardened after 9/11; during his 2002 State of the Union address, President Bush labeled North Korea as part of an “axis of evil” along with Iraq and Iran. Shortly thereafter, a leak of the administration’s classified Nuclear Posture Review revealed that North Korea was one of seven countries identified as possible nuclear targets in a military contingency; Pyongyang condemned this development as a violation of previous U.S. security assurances.

 In October 2002, amidst mounting evidence of North Korea’s covert efforts to acquire a uranium enrichment program, the Bush administration sent a delegation led by Assistant Secretary of State James Kelly to confront Pyongyang on this issue. During a contentious meeting, Kelly’s North Korean counterpart reportedly stated that his country had the right to possess nuclear weapons; acknowledged U.S. claims about its enrichment program; and hinted at a willingness to negotiate over the issue.22 (North Korea subsequently denied having a uranium enrichment program or admitting to its existence.) Following the encounter in Pyongyang, the United States declared that North Korea had violated the Agreed Framework, and announced a halt to all heavy fuel oil shipments.23 In response, North Korea declared the 1994 agreement nullified, withdrew from the NPT, and began reprocessing spent fuel from its reactor at Yongbyon to extract plutonium. With the collapse of the Agreed Framework, Pyongyang began speaking openly about building up its “nuclear deterrent force” unless the U.S. ended its “hostile policy.”24

Six Party Talks

The U.S. responded to these developments with a two-track policy of diplomacy and pressure, but internal divisions within the Bush administration meant that these two tracks did not always work in tandem. On the diplomatic track, the U.S., China, and North Korea began trilateral talks on the North’s nuclear program in April 2003, which soon evolved into Six Party Talks incorporating Japan, South Korea, and Russia. The Bush administration insisted on a multilateral format in the belief that it would internationalize the issue of North Korea’s nuclear program and put additional diplomatic pressure on Pyongyang.25 The stated U.S. goal for these negotiations was “complete, verifiable, irreversible dismantlement” of North Korea’s nuclear programs. On a separate pressure track, the U.S. formed an “Illicit Activities Initiative” designed to cut off Pyongyang’s access to hard currency obtained through drug smuggling, counterfeiting, and money laundering – activities that appeared to generate a sizeable proportion of the country’s export earnings.26

After two years of little diplomatic progress – during which North Korea reprocessed enough spent fuel to produce plutonium for at least half a dozen simple nuclear weapons – on September 19, 2005 the Six Parties announced a Joint Statement on denuclearization. The statement committed North Korea to abandoning its nuclear programs and returning to the NPT in exchange for food and energy assistance from the other Six Party members. It also outlined the parameters of future negotiations, including the normalization of North Korean relations with the United States, Japan and South Korea, and papered over Pyongyang’s demands for the provision of light-water reactors by stating that the topic would be discussed “at an appropriate time.”27 However, this agreement proved to be stillborn. Shortly before the talks had concluded, the U.S. Treasury Department had designated a Macau-based bank, Banco Delta Asia (BDA), as a “primary money laundering concern” due to its financial facilitation of North Korean illicit activities, leading the Macau government to freeze approximately $25 million in North Korean assets in the bank. After signing on to the Joint Statement, North Korea raised objections related to both this action and to the LWR issue, leading to another deadlock at the negotiating table. 

As diplomatic efforts hit a standstill, the U.S. followed up on the Treasury Department action with a campaign to pressure overseas financial institutions to avoid doing business with North Korea, and in July 2006 North Korea ended its missile test moratorium with the launch of a long-range Taepodong-2 missile. Several months later, Pyongyang conducted its first nuclear test, bringing a renewed sense of urgency to the nuclear crisis. The UN Security Council responded by condemning the test and adopting its first Chapter VII sanctions resolution targeted at North Korea’s nuclear and ballistic missile programs. Amidst this worsening situation, the Bush administration decided to intensify its diplomatic efforts, with a short-term focus on halting the threat posed by North Korea’s ongoing plutonium production.

Initial steps in this direction gained some traction, with the U.S., South Korea, Japan, China, and Russia more aligned in their approaches toward North Korea than they had previously been. In February 2007, the resumed Six Party Talks produced an agreement on initial actions toward denuclearization. As first steps, North Korea would halt operations at its Yongbyon facility, while other members of the Six Party Talks would provide North Korea with heavy fuel oil and form new working groups to discuss the implementation of various aspects the September 19 Joint Statement. As part of a side arrangement, the U.S. also agreed to facilitate the return of the frozen BDA funds to North Korea.

Upon receipt of these funds, North Korea allowed IAEA inspectors to return to the country to monitor, inspect, and verify the shutdown of the nuclear facilities at Yongbyon. Talks on subsequent steps continued despite revelations that North Korea, possibly since as early as 1997, had secretly assisted in the construction of a nuclear reactor in Syria designed for plutonium production. (An Israeli raid in September 2007 destroyed this facility before it became operational.)28 The Six Parties reached a second-phase implementation agreement in October, with North Korea agreeing to disable its nuclear facilities at Yongbyon and submit a declaration of “all its nuclear programs,” in return for the U.S. removing North Korea’s designation as a state sponsor of terrorism and ending sanctions imposed under the Trading with the Enemy Act. Heavy fuel oil shipments to North Korea would also continue.29

Over the course of the next year, implementation of this second-phase agreement became increasingly fraught. Negotiations were hampered by Pyongyang’s deteriorating relations with Tokyo (over the unresolved abductions of Japanese citizens by North Korea decades early) and with Seoul (over the tougher stance taken by a newly-elected conservative government), as well as by the uncertainties engendered by Kim Jong Il’s August 2008 stroke and the start of a leadership succession process. More fundamentally, however, North Korea’s refusal to be forthcoming about its uranium enrichment program and to accept intrusive verification measures proved to be insurmountable barriers to progress. After months of back-and-forth negotiations, during which North Korea slowed the disablement process to protest delays in promised heavy fuel oil shipments, in June 2008 Pyongyang submitted a declaration detailing the extent of its nuclear program. However, this document only provided details on North Korean plutonium production, and nothing about the country’s uranium enrichment program, its proliferation activities abroad, or its weaponization efforts.30

Amidst internal battles within the Bush administration about how to respond, the U.S decided to move forward with negotiations to disable the plutonium production facilities at Yongbyon, while linking North Korea’s delisting as a state sponsor of terror to its willingness to accept a verification regime (which would presumably account for its enrichment program).31 As Pyongyang submitted its declaration, President Bush terminated the application of sanctions on North Korea implemented under the U.S. Trading with the Enemy Act, while concurrently reinstating many of these sanctions under a different legal authority.32 Soon afterwards, North Korea demolished the cooling tower at its Yongbyon reactor, providing a visible signal of the facility’s disablement.

As the Bush administration’s second term drew to an end, its diplomacy with North Korea began to unravel over the issue of verification. In October 2008, with Pyongyang threatening to walk away from talks, U.S. and North Korean negotiators reached a verbal agreement outlining a verification protocol, leading Washington to remove North Korea from the U.S. list of state sponsors of terrorism in order to keep talks moving forward.33 However, North Korea rejected subsequent efforts in the Six Party Talks to commit to a written verification regime under terms acceptable to the U.S. and its allies. Early the following year, with a new administration in office in Washington, North Korea attempted to launch a satellite using a multi-stage rocket, prompting a statement of condemnation from the UN Security Council. Pyongyang subsequently expelled international monitors from its Yongbyon nuclear complex, declared that it would no longer be bound by its previous agreements, and conducted a second nuclear test, spelling the end for the Six Party Talks.

Strategic Patience

President Barack Obama entered office with a publicly- and privately-expressed willingness to engage with Pyongyang. At the same time, Obama was determined – as he reportedly told his national security team shortly after taking office – to “break the cycle of provocation, extortion, and reward.”34 Facing the collapse of the Six Party Talks at the start of its tenure and repeated crises involving North Korea thereafter, the Obama administration engaged only episodically in talks with Pyongyang, and held mostly to a policy of what Secretary of State Hillary Clinton in December 2009 called “strategic patience.”35 This policy centered on a stated aversion to “rewarding bad behavior” on the part of North Korea, coupled with a conditional willingness to return to high-level talks if North Korea showed a serious commitment to negotiate an end to its nuclear program. It also entailed the gradual escalation of economic and diplomatic pressure on Pyongyang in response to provocations.

Supporters of this approach defended it as the least bad of a set of bad options. Advocates of engagement, however, criticized strategic patience as fatalistic and unproductive in the face of a worsening nuclear threat, and argued that the approach was buoyed by wishful thinking about a failed leadership succession process in North Korea. More conservative critics of strategic patience similarly faulted the approach as overly disengaged and risk averse, but called for dramatically escalating sanctions and pressure rather than an immediate return to the negotiating table.36

In the months after its second nuclear test, Pyongyang gave mixed signals about its willingness to return to dialogue, showing a stated desire to improve relations with the U.S. but not necessarily to abandon its nuclear arsenal. In August 2009, North Korea secured a visit by Bill Clinton to Pyongyang in return for a promise to release two detained American journalists, during which Clinton and Kim Jong Il held a long (though unofficial) meeting on addressing the barriers to improved U.S.-DPRK relations. Stephen Bosworth, the State Department’s Special Representative for North Korea Policy, followed up with a December 2009 visit to discuss the possible resumption of the Six Party Talks.

Yet tensions ramped up again a few months thereafter, when a North Korean submarine – perhaps seeking retribution for an earlier naval skirmish in the disputed waters of the West Sea – torpedoed a South Korean naval ship, killing 46 South Korean sailors.37 Later in the year, North Korea fired artillery shells at South Korea’s Yeonpyeong Island as ROK military drills were taking place there, leading to the deaths of two South Korean soldiers, two South Korean civilians, and an unknown number of North Koreans from the South’s return fire. The U.S. and South Korea responded to these incidents with military shows of force, and Seoul cut off all avenues of economic engagement with Pyongyang other than the Kaesong Industrial Complex, an inter-Korean industrial park located just north of the DMZ. As military tensions heightened on the Peninsula, concerns over its nuclear capabilities also increased as Pyongyang (in a reversal from its longstanding position in the Six Party Talks) declared it possessed a uranium enrichment program and showed a visiting U.S. nongovernmental delegation a “modern, small industrial-scale” enrichment facility at Yongbyon.38

Facing the prospect of a gradual but unencumbered expansion of North Korea’s nuclear arsenal, the Obama administration engaged in three rounds of exploratory bilateral talks with North Korea from July through December 2011. Negotiations were temporarily halted due to the death of Kim Jong Il, but resumed in February 2012. On February 29, the U.S. and DPRK separately issued statements describing an agreement they had reached. Under the so-called “Leap Day” deal, the U.S. would provide North Korea with 240,000 metric tons of nutritional assistance, while the North agreed to implement a moratorium on long-range missile launches, nuclear tests, and nuclear activities at Yongbyon including uranium enrichment, as well as to allow IAEA inspections of known nuclear sites.39

Shortly after the agreement was rolled out, North Korea announced its intention to launch a satellite into orbit, claiming that “the launch of the working satellite is an issue fundamentally different from that of a long-range missile” and therefore was not a violation of the deal.40 Washington and the UN Security Council disagreed. Despite the U.S. reportedly sending envoys to Pyongyang on a secret mission to dissuade North Korea from following through with its plan, the launch was carried out a few days before the 100th anniversary of Kim Il Sung’s birthday. The launch failed to put a satellite into orbit, and led the U.S. to cancel the planned nutritional assistance package. A month later, the DPRK revised its constitution to declare itself a “nuclear power and an invincible military power” – demonstrating a deepening public commitment to its nuclear program under the country’s new leader, Kim Jong Un.41 North Korea conducted a more successful follow-up satellite launch in December 2012, followed once again by UN Security Council condemnation, another North Korean nuclear test, and new U.S. and international sanctions.

Tensions hit a peak the following spring as Pyongyang vehemently denounced the onset of annual U.S.-ROK joint military exercises, the scope of which had been expanded to include flights by nuclear-capable U.S. bombers. Over the course of two months, North Korea called the Armistice Agreement “completely nullified”; declared that a “state of war” with South Korea was in effect; announced the intended restart of its disabled reactor at Yongbyon; and temporarily closed the inter-Korean Kaesong Industrial Complex.42 In the midst of the crisis, the Workers’ Party of Korea Central Committee met to adopt the “Byungjin line” calling for the simultaneous development of North Korea’s economy and its nuclear arsenal, which Kim Jong Un insisted “can never be abandoned as long as the imperialists and nuclear threats exist on earth.”43

Although the frequency of threats and provocations subsided after a few months, tensions between the U.S. and North Korea generally remained high throughout the remainder of the Obama administration. In early 2014, a UN Commission of Inquiry investigation on North Korean human rights abuses found evidence of “systematic, widespread, and gross human rights violations” and called for the referral of the situation to the International Criminal Court. The report and the strong U.S. support for its conclusions evinced a furious North Korean reaction, with DPRK diplomats denouncing the human rights criticism as part of a U.S. “hostile policy.”44 In late 2014, the film studio Sony Pictures suffered a major hacking incident tied to its production of a satirical film that depicted the attempted assassination of Kim Jong Un; the FBI attributed the attack to North Korea, showcasing a growing U.S. and international concern about the county’s cyber activities.45 Beginning in 2014, North Korea also began dramatically increasing its pace of testing short- and medium-range missiles, marking the start of a major effort to expand its ballistic missile program.46

During its second term, the Obama administration did not return to a sustained dialogue with North Korea on denuclearization, despite periodic back-channel efforts to get diplomacy back on track. In June 2013, a high-level North Korean statement called for high-level talks with the U.S. without preconditions, and said that Pyongyang was committed to the denuclearization of the Korean Peninsula.47 However, with North Korea unwilling to agree to any preconditions to negotiations, such as reaffirmation of the 2005 Joint Statement of the Six Party Talks or a pledge to suspend nuclear and missile testing, the Obama administration dismissed this overture as lacking sincerity.48 A North Korean offer in early 2015 to suspend nuclear tests in return for the cancellation of U.S.-ROK military exercises – a “freeze-for-freeze” proposal – was similarly ignored.49 In early 2016 the Obama administration privately offered to begin peace treaty talks with North Korea if denuclearization was part of the agenda, appearing to drop its previous preconditions for dialogue. However, Pyongyang reportedly dismissed the offer and conducted its fourth nuclear test shortly after receiving it.50

Toward Maximum Pressure

By the time of this nuclear test, the Obama administration’s policy toward North Korea was coming under increasing strain. Kim Jong Un appeared firmly entrenched in power, with his Byungjin policy of nukes and butter paying dividends. In spite of international sanctions, North Korea’s economy had been enjoying modest growth, thanks to both greater tolerance toward the role of markets and to a rapid increase in trade with China during its leadership transition period.51 As North Korea’s economic ties with China deepened, its overseas procurement network for its nuclear and missile programs also became more effective and sophisticated, paving the way for rapid advances in the country’s WMD capabilities.52

The fourth nuclear test marked a turning point and the start of an international campaign of heightened pressure against North Korea’s nuclear program. In February 2016, the Park Geun-hye administration in Seoul shut down operations at the Kaesong Industrial Complex, cutting off the last remaining – and largest – channel of inter-Korean engagement. At the UN, China and Russia gave their support to a sanctions resolution that targeted North Korea’s non-military exports, including its lucrative foreign coal sales, for the first time.53 In Washington, Congress and the White House worked to significantly broaden the scope of U.S. sanctions, with a major new sanctions law mandating the use of secondary sanctions against foreign enablers of Pyongyang’s WMD programs. A July 2016 U.S. sanctions designation personally targeted Kim Jong Un for human rights violations, prompting Pyongyang to cut off all official contact with the U.S. for the remainder of the Obama administration’s term.54

Shortly before Donald Trump entered the White House, President Obama reportedly warned him that North Korea’s nuclear and missile programs would be the most urgent challenge Trump would confront.55 Trump did not have a particularly strong focus on the Korean Peninsula on the campaign trail, despite raising headlines for suggesting that Japan and South Korea should develop their own nuclear weapons and claiming that the two countries did not pay enough of the costs of hosting U.S. troops. After the election, however, Kim Jong Un announced his intention to test launch an intercontinental ballistic missile (ICBM), prompting Trump to tweet that a North Korean nuclear-armed ICBM capability “won’t happen!”56 This set the tone for Trump’s first year in office, as his administration pursued a policy of “maximum pressure” and North Korea conducted a series of long-range missile tests.

In some ways, the maximum pressure campaign was a continuation of the policy pursued by the Obama administration in its last year. A series of new UN sanctions resolutions aimed to cut off nearly all of Pyongyang’s sources for earning hard currency, and began to crack down on North Korea’s ability to import fuel and other key commodities. By the summer of 2017, China appeared to be taking significant steps to enforce these UN sanctions, with the Trump administration tying its forbearance on U.S-China trade issues to Beijing’s cooperation on pressuring North Korea. Concurrently, the U.S. ramped up its enforcement of sanctions by targeting North Korean shipping and blacklisting small banks based in China and Eastern Europe. As part of this pressure campaign, U.S. diplomats across the globe also worked to persuade countries to cut their economic and diplomatic ties with Pyongyang

In conjunction with these efforts, some members of the Trump administration stressed that the U.S. remained open to negotiations with North Korea, and back channel diplomacy between the two countries quietly resumed. Secretary of State Rex Tillerson and Secretary of Defense James Mattis publicly emphasized that the U.S. did not seek regime change in North Korea, and Tillerson repeatedly indicated that the U.S. was open to engaging in talks with Pyongyang.57 However, these overtures may have been undercut by the perception that the White House was not fully behind them, with Trump tweeting that his top diplomat was “wasting his time trying to negotiate with Little Rocket Man.”58

Trump’s vituperative and combative rhetoric toward Pyongyang, paired with his administration’s apparently serious consideration of military options, marked a significant break with his predecessor’s approach to North Korea policy. In August 2017, in the wake of two North Korean tests of its Hwasong-14 ICBM, Trump told the media that if North Korea kept threatening the United States, it would “be met with fire and fury like the world has never seen.”59 The following month, in an address to the UN General Assembly, Trump said that if the U.S. “is forced to defend itself or its allies, we will have no choice but to totally destroy North Korea.”60

North Korea responded to these remarks with its own escalation of rhetoric and threats. After Trump’s “fire and fury” remark, the Korean People’s Army’s Strategic Force threatened to fire an array of long-range missiles at the surrounding waters of the U.S. territory of Guam.61 In response to the UN speech, Kim Jong Un gave an unusual public address threatening to “tame the mentally deranged U.S. dotard with fire.” The DPRK Foreign Minister warned that his country might conduct an atmospheric thermonuclear test over the Pacific Ocean, presumably after launching the warhead from a ballistic missile.62 North Korea did not follow through with these specific threats, but it did conduct what appeared to be its first thermonuclear test and a test of the Hwasong-15 ICBM, which appeared capable of reaching the entire continental United States.

The last element of the Trump administration’s “maximum pressure” campaign was making high-profile shows of military force on or near the Korean Peninsula, as well as signaling that Washington was prepared to take military action to prevent North Korea from being able to threaten the U.S. with nuclear-armed missiles. As tensions with North Korea reached a peak, talk in Washington of preventive military action against North Korea became increasingly common. National Security Advisor H.R. McMaster publicly argued that “classical deterrence theory” couldn’t apply to North Korea, given the regime’s brutality and aggressiveness.63 Senator Lindsey Graham, a close ally of the administration on North Korea policy, argued to the media that a war on the Peninsula would be “worth it” if it stopped a nuclear threat to the United States.64

By the end of 2017, North Korea was – by most expert accounts – nearing the finish line in its development of nuclear-armed ICBMs that could credibly threaten the United States. Although North Korea’s test flights of its Hwasong-14 and Hwasong-15 ICBMs appeared to have been largely successful, questions remained about the reliability of these missiles and Pyongyang’s development of re-entry vehicles to deliver its warheads. A U.S. intelligence assessment leaked to the press in August 2017 estimated that North Korea could possess enough fissile material for up to sixty nuclear weapons.65 Yet after North Korea’s Hwasong-15 test, with Washington discussing the prospect of military action, Kim Jong Un declared the country’s nuclear program to be “complete,” and in his 2018 New Year’s Address indicated a plan to shift from testing and development to the mass production of nuclear warheads and ballistic missiles. In this speech, Kim also extended an olive branch to Seoul, indicating a willingness to participate in the upcoming Winter Olympics in South Korea – and advancing an opening gambit in a new round of international engagement and nuclear diplomacy.66

Toward Maximum Engagement

Kim Jong-un’s New Year’s speech prompted a positive response from the progressive new Moon Jae-in administration in South Korea almost immediately, and ultimately led to a dramatic U-turn in the direction of U.S. policy as well. Inter-Korean talks soon led to an agreement to form a joint women’s hockey team for the Olympics, and for a North Korean delegation including Kim Jong Un’s sister, Kim Yo Jong, to attend the opening ceremony. As inter-Korean relations began to warm, U.S. intelligence agencies were also quietly making contact with their North Korean counterparts, establishing a secret back channel for talks and bypassing the engagement efforts being made by the State Department.67 In March, Kim Jong Un sent a message via two high-ranking South Korean officials that he sought a summit meeting with Donald Trump to discuss the denuclearization of the Korean Peninsula. Trump accepted the offer on the spot, sending CIA Director (and his nominee to replace Tillerson as Secretary of State) Mike Pompeo to Pyongyang to hold a secret preliminary meeting with Kim Jong Un.68

With this diplomatic coup in hand, Kim convened a meeting of the Central Committee of the Workers’ Party of Korea, declared the two-track Byungjin policy of parallel economic and nuclear development to have been victorious, and announced that the “new strategic line” would prioritize “socialist economic construction.” Kim stated that additional nuclear and long-range missile tests wouldn’t be necessary for the time being, pledging to close the country’s nuclear test site and saying that, if the country’s security were guaranteed, it would be willing “to make positive contributions to the building of the world free from nuclear weapons.”69 Shortly thereafter, Kim met with Moon Jae-in on the southern side of the Joint Security Area at Panmunjom, pledging to improve relations, reduce military tensions, and realize the “denuclearization of the Korean Peninsula.”70 Prior to the summit, North Korea also signaled that it would not demand the withdrawal of U.S. troops from the Peninsula in return for denuclearization.71

The road from the Panmunjom summit to Trump’s meeting with Kim Jong-un was short but filled with twists and turns nonetheless. In May, Secretary of State Pompeo made a return visit to Pyongyang, winning the release of three Americans who had been detained by North Korea. A few weeks later, North Korea invited an international group of journalists – but not technical experts – to witness the demolition of its nuclear test site. With the Trump administration insisting that “maximum pressure” would continue until North Korea achieved complete, verifiable, irreversible denuclearization, National Security Advisor John Bolton urged North Korea to follow the “Libya model” in denuclearization talks.72 Pyongyang rebuked Bolton for his reference to what it considered a model for surrender and regime change; this prompted a round of escalating rhetoric from Washington and Pyongyang that culminated in a open letter from Trump to Kim announcing the cancellation of their planned summit. Another hastily-convened meeting between Kim Jong Un and Moon Jae-in at Panmunjom, followed by a visit by North Korean regime heavyweight Kim Yong Chol to New York and Washington, put plans for the meeting back on track, with U.S. and North Korean officials scrambling to work out the agenda and details for a June 12 meeting in Singapore.

The  Trump-Kim summit, held at a secluded hotel on Singapore’s Sentosa Island, marked the first meeting between the leaders of the U.S. and North Korea. The Joint Statement released at the summit was similar in many respects to the U.S.-DPRK statements of years past, promising improved relations, a lasting peace regime, and (in language noticeably more vague than that of past agreements) the North’s “commitment to work toward complete denuclearization of the Korean Peninsula.”73 The document committed the two sides to hold follow-up negotiations, and to resume cooperation on the recovery and repatriation of the remains of Korean War-era U.S. service members from the North. (These recovery missions had been suspended since 2005.) In a press conference held after the summit, Trump said that he had agreed to suspend U.S.-ROK joint military exercises and indicated that Kim had promised to dismantle a missile engine testing site.74 During the summit, Trump also reportedly agreed to move swiftly to sign a declaration on the end of the Korean War.75 A few days after the summit, Trump declared the problem of North Korea’s nuclear program to be “largely solved.”76

After Singapore