Save Preemption for Imminent North Korean Attack

Report Missile Defense

Save Preemption for Imminent North Korean Attack

March 1, 2017 34 min read Download Report
Bruce Klingner
Senior Research Fellow, Northeast Asia
Bruce Klingner specializes in Korean and Japanese affairs as the Senior Research Fellow for Northeast Asia.


North Korea’s growing nuclear and missile capabilities are an existential threat to South Korea and Japan and will soon be a direct threat to the continental United States. Washington should make unambiguously clear that it will deter, defend, and if necessary defeat the North Korean military threat to ourselves and our allies. If it is determined that a North Korean missile flight might be directed at U.S. territory, the U.S. Administration should take all necessary actions to defend U.S. sovereignty and the American people. However, preemptive allied attacks should be reserved for convincing signs of imminent North Korean attack, not launched to fulfill pundits’ oft-spoken vows to shoot down North Korean missiles during test flights or while on launch gantries. The U.S. should be steadfast in its defense of South Korea, but preemptive attacks on test flights that do not clearly pose a security threat could trigger a war with a nuclear-armed state that also has a large conventional military force poised along the border with South Korea.

Key Takeaways

Kim Jong-un is pushing forward to deploy missiles that could target bases in Guam and continues to develop a nuclear-tipped ICBM to threaten the America homeland.

The pace of North Korean nuclear and missile tests reflects Kim Jong-un’s intent to deploy a spectrum of missile systems of complementary ranges to threaten the U.S.

Preemptive allied attacks should be reserved for convincing signs of imminent North Korean attack.

The security situation on the Korean Peninsula is dire and worsening. There is a disturbingly long list of reasons to be pessimistic about maintaining peace and stability in northeast Asia.

  • North Korea’s decades-long quest for an unambiguous ability to target the U.S. with a nuclear-tipped intercontinental ballistic missile (ICBM) may be entering endgame. Pyongyang undertook a robust nuclear and missile test program in 2016, achieving several breakthroughs.

  • Kim Jong-un has asserted that the regime has “reached the final stage of preparations to test-launch an intercontinental ballistic missile” and will continue to increase “the capability for preemptive strike.”

  • Pyongyang has declared that the “ICBM will be launched anytime and anywhere.”

  • Pyongyang has repeatedly vowed that it will never abandon its nuclear arsenal and dismissed the potential for denuclearization negotiations. A senior-ranking North Korea defector asserted, “As long as Kim Jong-un is in power, North Korea will never give up its nuclear weapons, even if it’s offered $1 trillion or $10 trillion in rewards.”[REF]

  • U.S. policymakers, lawmakers, and experts predominantly assess that the time for dialogue with Kim Jong-un has passed and that the U.S. must impose augmented sanctions to tighten the economic noose on North Korea. Although such sanctions are the proper policy, they do carry the risk of strong reactions from Pyongyang and Beijing.

  • South Korea has growing concerns about U.S. capability, resolve, and willingness to defend their country, particularly once North Korea demonstrates an unambiguous ability to threaten the U.S. mainland with nuclear weapons.

  • Advocacy is growing for preemptive military actions against North Korea, mimicking the regime’s comments about its own preemption plans. Preemptive action raises the risk of military conflict, either intentionally or through miscalculation.

North Korea’s growing nuclear and missile capabilities are an existential threat to South Korea and Japan and will soon be a direct threat to the continental United States. Washington should make unambiguously clear that it will deter, defend, and if necessary defeat the North Korean military threat to ourselves and our allies. Such a policy requires repeated expressions of steadfast resolve coupled with remedial steps to reverse declines in American military capabilities.

If it is determined that a North Korean missile flight might be directed at U.S. territory, the U.S. Administration should take all necessary actions to defend U.S. sovereignty and the American people. However, preemptive allied attacks should be reserved for convincing signs of imminent North Korean attack, not launched to fulfill pundits’ oft-spoken vows to shoot down North Korean missiles during test flights or while on launch gantries.

Preemptive attacks on test flights that do not clearly pose a security threat could trigger a war with a nuclear-armed state that also has a large conventional military force poised along the border with South Korea. While the U.S. should be steadfast in its defense of its territory and its allies, it should not be overeager to “cry havoc and let slip the dogs of war.”

Growing Advocacy of Preemption

The imminence of Pyongyang’s crossing of the ICBM threshold has stimulated growing calls for the U.S. to conduct a preemptive attack to prevent it. There have been previous calls for such action, the most famous being in 2006 when former Secretary of Defense William Perry and future Secretary of Defense Ashton Carter declared that since “diplomacy has failed,” the U.S. should “strike and destroy the North Korean Taepodong missile before it can be launched” from its gantry on a test flight.[REF] Perry and Carter advocated the attack even against the vigorous opposition of South Korea and dismissed an “all-out” North Korean military response as “unlikely.” Eleven years later, however, Perry wrote that he would not recommend such a strike “because of the very great risk for South Korea.”[REF]

Since North Korea’s fifth nuclear test in September 2016, there have been widespread calls for preemptive attacks in both Washington and Seoul. For example:

  • The former chairman of the Joint Chiefs of Staff, retired Admiral Mike Mullen, has emphasized the need to augment U.S. military capabilities to “theoretically take out launch capabilities on the launch pad or take them out once they are launched.”[REF]

  • In November 2016, General Walter Sharp, former commander of U.S. Forces Korea, stated that in the event North Korea puts a three-stage Taepo Dong 2 on the launchpad, and if the U.S. is unsure of its payload, then Washington should conduct a preemptive attack and destroy the missile. Sharp commented that the U.S. cannot risk relying solely on missile defense to counter North Korean long-range missiles.[REF]
  • In December 2016, Senator Lindsey Graham (R–SC) commented that he would introduce legislation to authorize the President to use military force preemptively to stop Pyongyang from completing the development of its ICBM.[REF]

  • In January 2017, Senator Bob Corker (R–TN), chairman of the Senate Foreign Relations Committee, suggested that the U.S. should be “be prepared to preemptively strike a North Korean ICBM.”[REF]

  • Polls show that a growing number of South Koreans support a preemptive strike on North Korea “in case of emergency.” A September 2016 poll, for example, showed that 43 percent of respondents supported a preemptive attack, up from 36 percent in 2013.[REF]

Growing North Korean Threat

North Korea’s nuclear and missile capabilities are already an existential threat to South Korea and Japan. South Korean President Park Geun-hye described the capabilities as a “dagger to our throats.”[REF] North Korean leader Kim Jong-un is pushing forward rapidly to deploy missiles that could target U.S. bases in Guam and continues to develop a nuclear-tipped ICBM to threaten the American homeland.

Shortly after assuming power in late 2011, Kim Jong-un directed the creation of a new war plan to complete an invasion of South Korea within a week using asymmetric capabilities (including nuclear weapons and missiles). A senior North Korean military defector has indicated that the North intends to occupy the entire South Korean territory within seven days before U.S. reinforcements arrive.[REF]

During Kim’s four-year reign, Pyongyang has conducted more than twice as many missile tests as his father Kim Jong Il did during his 17 years in office. The accelerated pace of North Korean nuclear and missile tests reflects Kim Jong-un’s intent to deploy a spectrum of missile systems of complementary ranges to threaten the U.S. and its allies with nuclear weapons.

Submarine-Launched Ballistic Missiles. In August 2016, North Korea conducted its most successful test launch of a submarine-launched ballistic missile (SLBM). The missile traveled 500 kilometers (300 miles) but with an unusually high trajectory. If launched on a regular high trajectory, the missile might have traveled over 1,000 km.[REF]

The South Korean Ministry of National Defense previously assessed that it would be three to four years before North Korea would be able to deploy a submarine ballistic missile force. However, after the successful SLBM test, some South Korean military authorities warned that deployment could occur within a year.[REF]

South Korea does not currently have defenses against submarine-launched ballistic missiles. The SM-2 missile currently deployed on South Korean destroyers provides protection only against anti-ship missiles. South Korea has recently expressed interest in the U.S.-developed SM-3[REF] or SM-6 ship-borne systems[REF] to provide anti-submarine-launched missile defense.

North Korea’s old and noisy submarines may not appear to be a submarine-based ballistic missile threat. However, in 2010, a North Korean submarine sank the South Korean naval corvette Cheonan in South Korean waters. In August 2015, 50 North Korean submarines—70 percent of the fleet—left port and disappeared[REF] despite allied monitoring efforts.

Mobile Intermediate-Range Ballistic Missiles. In June 2016, North Korea successfully tested a Musudan intermediate-range missile. North Korea announced that the missile was flown at an unusually high trajectory so as not to overfly Japan and also so as to verify “the heat-resistance capability of warhead in the re-entry section and its flight stability,” including for strategic nuclear weapons.[REF] Had the missile been flown on a normal trajectory, it could have traveled 2,500 miles, putting U.S. bases in Guam at risk.[REF]

Medium-Range Ballistic Missiles. Pyongyang conducted several successful No Dong medium-range missile tests in 2016. North Korea state media announced that the missile launches were practice drills for preemptive air-burst nuclear attacks[REF] on South Korean ports and airfields where U.S. reinforcement forces would arrive during a military crisis. A North Korean media-released photo showed that the missile’s range would encompass all of South Korea, including the port of Busan.[REF]

Intercontinental Ballistic Missiles. In February 2016, North Korea again used a Taepo Dong missile to put a satellite into orbit—the same technology needed to launch an ICBM nuclear warhead. Assessments indicate that the satellite was approximately 450 pounds, twice as heavy a payload as the previous successful satellite launch in December 2012, and that the missile may have a range of 13,000 km,[REF] putting the entire continental U.S. within range. Several U.S. four-star commanders have stated that North Korea has—or the U.S. must assume that it has—a nuclear ICBM capability. Other experts assess that Pyongyang will have an ICBM capability in one to two years.[REF]

In April 2016, North Korea released photos of a successful static engine test of a “new type high-power engine of inter-continental ballistic rocket.” Two non-government experts assessed that the engines used higher-energy propellants than previously assumed so that the road-mobile KN-08/14 ICBM could deliver a 500-kilogram nuclear warhead to a target within a range of 10,000–13,000 km. The range is greater than previously estimated, allowing North Korea to reach the east coast of the U.S. The missile might also be deployable sooner than the two to three years of previous estimates.[REF]

Nuclear Arsenal. North Korea has declared that it has achieved “standardized” miniaturized nuclear warheads capable of being fitted to a variety of missiles. U.S. experts estimate that Pyongyang currently has 10–16 nuclear weapons.[REF] Pyongyang has potentially developed boosted fission weapons and levitated pit warheads, the latter allowing weapons requiring less fissile material per bomb.

In March 2015, Admiral Cecil Haney, commander of U.S. Strategic Command, testified that he believes North Korea has “already miniaturized” some of its nuclear weapons.[REF] Admiral Bill Gortney, commander of North American Aerospace Defense Command, stated that North Korea can put a nuclear warhead on the No Dong[REF] medium-range ballistic missile, which is capable of reaching all of South Korea and Japan.

Assessing Progress in 2016

In 2016, North Korea increased the frequency, sophistication, and success rate of its nuclear and missile tests. In addition to two nuclear tests, North Korea:

  • Successfully tested an intercontinental ballistic missile;

  • Achieved breakthrough successes in the first flight tests of a road-mobile intermediate-range missile and a submarine-launched ballistic missile;

  • Upgraded medium- and short-range missiles; and

  • Displayed and tested re-entry vehicle technology, a new solid-fuel rocket engine, and an improved liquid-fuel ICBM engine.

Pyongyang is developing mobile land-based and sea-based missile systems that are harder to detect and target. The success of its solid-fuel engine tests and launches reduces the time necessary for launch, thereby constraining warning time. Simultaneously launching multiple missiles from the field shows an enhanced ability to guarantee survivability of nuclear forces, ensure regime survival, reduce viability of allied preemptive attacks, launch surprise nuclear attacks, engage in coercive diplomacy, and have a second-strike capability.

Growing Concerns Are Catalyst for New Military Options

The increasing North Korean threat has aggravated long-standing allied concerns about U.S. abandonment that were exacerbated by perceptions of diminished U.S. military capabilities and resolve during the Obama Administration. There are greater South Korean fears of a decoupled alliance in which the U.S. “wouldn’t trade Los Angeles for Seoul” once North Korea demonstrates an unambiguous capability to threaten the continental U.S. with nuclear ICBMs.

These factors have caused more advocacy in South Korea for a range of military options, including:

  • Reintroduction of U.S. tactical nuclear weapons that were withdrawn in the 1990s,

  • Development of an indigenous South Korean nuclear program, and

  • Greater reliance on preemption strategies.

Neither the reintroduction of U.S. tactical nuclear weapons into South Korea nor an indigenous South Korean nuclear weapons program makes military sense. The ground-based U.S. nuclear weapons that were withdrawn are no longer in the U.S. inventory. There are U.S. tactical nuclear weapons in the Pacific Theater, but they are deployed on ships, submarines, and airplanes—all of which North Korea is unable to target given their mobile, elusive nature.

To remove nuclear weapons from those platforms and put them into underground bunkers in South Korea would be counterproductive. It would lengthen their response time since they would need to be returned from the bunker to their delivery platforms, would degrade their stealthy nature by putting them into an easily identifiable fixed ground site, and thus would undermine their deterrent and defense capabilities. Putting such high-value weapons in easily targetable bunkers would increase the likelihood that North Korea might attempt a preemptive attack during a crisis.

If South Korea were to begin developing nuclear weapons, it would become the target of international sanctions, would be diplomatically isolated, and could suffer the collapse of its alliance with the U.S. Moreover, an indigenous nuclear program would divert excessive funding from South Korea’s defense budget away from critical requirements simply to duplicate an existing capability provided by the U.S.

Increasing Preemptive Capabilities

In recent years, the U.S.–South Korean alliance has altered its operational plan for conflict on the Korean Peninsula to include preemptive attack scenarios. In 2015, the U.S. and South Korea adopted a new war plan, Operational Plan 5015, which reportedly includes options for a preemptive strike on the North’s nuclear and missile facilities and decapitation attacks on North Korea’s leadership, including Kim Jong-un. Joint U.S.–South Korean military exercises in 2016 reportedly practiced some of these scenarios.[REF]

Separately, South Korea has developed independent preemptive attack plans and has acquired weapons capable of attacking North Korean weapons of mass destruction. South Korea has adopted a “3K Defense System” consisting of the following:

  • Kill Chain detection and preemptive attack system to attack North Korean missiles prior to launch;

  • Korea Air and Missile Defense System (KAMD) to intercept North Korean missiles in mid-air; and

  • Korea Massive Punishment and Retaliation (KMPR) to attack nuclear, missile, and leadership targets after attack or upon detection of signs of imminent North Korean attack.

After North Korea’s September 2016 nuclear test, South Korean Defense Minister Han Min-Koo announced the KMPR strategy. Han testified that Seoul was “considering launching a Special Forces unit to assassinate North Korean leader Kim Jong-un.” The unit would take action if North Korea “shows clear signs of attacking South Korea.” A South Korean defense official added, “Should the North threaten to use nuclear weapons, we will use sophisticated guided weapon systems to strike its missile and launching facilities.”[REF]

South Korea has been adding military capabilities to improve its preemptive attack abilities. Under a 2012 agreement with the U.S., Seoul was allowed to produce ballistic missiles with an 800-km range (up from the previous limit of 300 km) with a 500-kg payload. South Korea can produce cruise missiles with a range of up to 1,500 km and is currently developing the Hyunmoo-2 SSMs and Hyunmoo-3 cruise missiles.

South Korea will also purchase additional long-range air-to-ground Taurus missiles from Germany. The missiles would be launched from F-15Ks to a range of 500 km. If fired from near the Demilitarized Zone (DMZ), the missiles could reach all of North Korea. The original plan was for 177 missiles by 2017; an additional 90 now will be procured before the end of 2018. Seoul will also purchase the Small Diameter Bomb-II, a U.S.-produced air-launched glide bomb, to target North Korea’s mobile missile launchers.[REF]

Dangerous Ramifications of Preemptive Attack

There is a distinct difference between using military force to prevent North Korea from attacking the U.S. with a nuclear-tipped missile and preventing Pyongyang from building or testing such a missile. The U.S. President already has the constitutional authority to take action against threats to the U.S., imminent or otherwise. U.S. military action in cases of an inbound missile or imminent nuclear attack, however, would be a defensive response.

By contrast, a U.S. military attack against production or test facilities of North Korea’s nuclear or missile programs would be an offensive action that could trigger an all-out war with a nuclear-armed North Korea. Pyongyang already has the ability to target South Korea and Japan with nuclear weapons and also has a million-man army poised just across the DMZ from South Korea. Without moving any military units, Pyongyang could unleash a devastating artillery attack on Seoul.

Preventing North Korea from Completing ICBM Development. Some experts advocate preemptive attack to prevent North Korea from completing the development of a nuclear ICBM that can threaten the U.S. However, they have not identified what technological milestone they would use military force to prevent, nor have they identified how the U.S. would know Pyongyang was on the verge of progressing beyond that milestone. This shortage of concrete information yields a number of pressing questions, including:

  • Given the opacity of North Korea, how likely is it that the U.S. Intelligence Community could provide comprehensive, actionable information in sufficient time to enable U.S. prior action?

  • What targets would need to be included to ensure that the capability is prevented—only missile test facilities or also missile and nuclear weapons research, production, and storage facilities?

  • Would military missile units also be included?

  • What mitigating actions would be taken to prevent a North Korean military response, including a potentially cataclysmic attack on Seoul?

  • How would China respond to an attack on its ally?

These are not moot questions. When then President-elect Donald Trump was told that North Korea had claimed it had reached the “final stage of preparations to test-launch an intercontinental ballistic missile,” he declared, “It won’t happen.” Kellyanne Conway, Counselor to the President, explained that Trump had sent a “clear warning” to North Korea and put Pyongyang “on notice.” She further commented that “The president of the United States will stand between them and missile capabilities.”[REF]

Has President Trump drawn a red line to use all means necessary to prevent North Korea from completing its ICBM program? Given the rapid pace of North Korea’s 2016 test program and the regime’s tendency to conduct provocations early in new U.S. and South Korean administrations, it might not be long before President Trump faces reports of another North Korean long-range missile or nuclear test.

North Korean Missile Test. Flippant advocacy of shooting down a North Korean missile during a test flight also has serious consequences. A lone North Korean missile on a test flight the trajectory of which is determined by U.S. intelligence satellites to be aimed only at open water does not pose an imminent or existential threat to the U.S.

Intercepting such a test flight could redirect international focus and anger away from North Korean violation of U.N. resolutions and toward the U.S. military action. In addition, regardless of whether such a missile interception constituted a formal act of war by the U.S., it would certainly be seen as provocative and could trigger a North Korean military response. In October 2015, Foreign Minister Ri Su-yong told the U.N. General Assembly that Pyongyang would respond “with all available self-defensive measures” if anyone tried to stop its “peaceful satellite launch.”

Would an allied attack on the North Korean missile in flight be reserved only for a situation in which the missile was assessed to be equipped with a nuclear weapon? What if it was assessed to have only a test instrumentation package, a nonmilitary satellite, or unknown payload?

Moreover, the U.S. and its allies likely could not intercept a North Korean missile on a test flight trajectory since it would be traveling outside the intercept of any allied ballistic missile defense (BMD) system. Ground-based systems such as Patriot-2/3 and Terminal High Altitude Area Defense (THAAD) can intercept incoming missiles only during the terminal phase of their flight and within the parameters of the radar and interceptor missiles. Ship-based systems such as SM-3 can intercept missiles at a greater altitude and range, but again within narrow parameters. For example, Japanese SM-3 missiles could not intercept North Korean missiles flying over—rather than toward—Japan since that trajectory would exceed the altitude range of the interceptor missiles.

Attacking a missile on its launch gantry at North Korea’s known fixed test launch sites would have a far greater likelihood of success. This is the scenario that William Perry and Ashton Carter advocated in 2006. However, what if the regime were going to test a road-mobile KN-08 or KN-14 ICBM? Would the U.S. attack missile launchers anywhere in North Korea based on the perception that they were going to conduct a test launch? Both scenarios carry a commensurately increased risk of a military response to attacks on North Korean soil.

Also, would such an attack be reserved for preventing test flights of ICBMs, or would it also include Musudan intermediate-range ballistic missiles that can threaten U.S. bases in Guam or No Dong medium-range missiles that can target South Korea, Japan, and U.S. forces stationed in both countries?

Imminent North Korean Attack. While the U.S. and South Korean presidents should consider a preemptive attack if an imminent North Korean nuclear attack is detected, such a scenario is also problematic. Such a preemptive allied attack, as opposed to responding to notification of inbound missiles, would likely be based on insufficient or imperfect intelligence collection and assessment. Imagine a U.S. or South Korean president faced with an intelligence briefing like the following:

Reconnaissance satellites have detected some North Korean mobile missiles in the field that are fueled and positioned for launch. We think we’ve identified them all, but since they are mobile, there could be others. We assess that they are equipped with nuclear warheads but can’t be sure. Based on the current tense situation, we believe that the missiles are preparing for a nuclear strike, but the regime could be attempting to send a political signal, or they may not have nuclear weapons and could just be out for routine training exercises.

Based on such information, the President would then need to decide whether to conduct a preemptive attack and possibly start another Korean War, this time with a nuclear North Korea. It could well be like another Cuban missile crisis but with Soviet missiles already fully operational in Cuba. Would the decision be made unilaterally or in conjunction with allies?

Greater Risk of Miscalculation

North Korea’s Preemption Threats. As North Korea’s nuclear and missile prowess has increased, so have its threats of a preemptive attack to forestall what it depicts as the rising risk of an allied preemptive attack. In October 2016, Lee Yong-pil, director of the North Korean Ministry of Foreign Affairs’ Institute for American Studies, declared, “A preemptive nuclear strike is not something the U.S. has a monopoly on. If we see that the U.S. would do it to us, we would do it first.”[REF]

In March 2016, the North Korean National Defense Commission warned of its “military counter-action for preemptive attack” ahead of the annual U.S.–South Korean military exercises. The military vowed to “launch an all-out offensive to decisively counter the U.S. and its followers’ hysteric nuclear war moves [and] take military counteraction for preemptive attack [and] offensive nuclear strike to [conduct] a sacred war of justice for reunification.” The regime also boasted of its “powerful nuclear strike means targeting the U.S. imperialist aggressor forces bases in the Asia-Pacific region and the U.S. mainland.” Concurrently, the North Korean Foreign Ministry declared that “[a] decisive preemptive attack is the only way for [North Korea] to beat back the sudden surprise attack of the U.S….”[REF]

South Korea Leaning Farther Forward. Seoul may become increasingly reliant on a preemption strategy because North Korea’s growing nuclear capabilities are an existential threat. One nuclear weapon over Seoul would threaten one-third of the nation’s entire population as well as its centralized government and business sectors. The loss of Seoul could lead to the end of the Korean nation.

South Korean officials also have privately expressed a perception that the U.S. “sits on its ally” by immediately trying to deescalate any situation before Seoul responds. As a result, South Korea might see utility in acting quickly before Washington intervenes and prevents action. All senior military commanders were replaced for responding with insufficient vigor to North Korea’s 2010 attacks on the Cheonan naval ship and Yeonpyeong Island. Being hesitant and cautious was penalized.

Preemption Through Miscalculation. With the international community imposing stronger sanctions, Kim Jong-un may perceive himself as painted into a corner and consequently take even more provocative and desperate steps than have been taken in the past. North Korea’s growing nuclear capability could give regime leaders a sense of impunity. They might become emboldened to conduct not only provocations, but also actual attacks, perceiving that they have undermined the U.S.’s extended deterrence guarantee by decoupling U.S. security from South Korea’s.

Advocacy of preemption both by North Korea and by U.S allies is destabilizing and could lead to greater potential for either side to miscalculate. Pyongyang may not realize that the more it achieves, demonstrates, and threatens to use its nuclear prowess, the more likely an allied action during a crisis becomes.

Each side could misinterpret the other’s intentions, thus fueling tension, intensifying a perceived need to escalate, and raising the risk of miscalculation, including preemptive attack. Even a tactical military incident on the Korean Peninsula always has the potential for escalating to a strategic clash. With no apparent off-ramp on the highway to a crisis, the danger of a military clash on the Korean Peninsula is again rising.

What the U.S. Should Do

To reduce advocacy for preemptive action, the U.S. should enhance perceptions of its commitment and capabilities. Specifically, the U.S. should:

  • Reserve preemptive attack for imminent North Korean attack. Neither the U.S. nor South Korea should initiate an attack on North Korea for crossing yet another technological threshold, such as an impending test launch of one missile or a successful long-range test demonstrating reentry vehicle capability. Such an attack would risk initiating a full-scale war with a nuclear nation. The more prudent course of action is to reserve a preemptive attack for a situation in which the Intelligence Community has strong evidence of imminent strategic nuclear attack on the U.S. or its allies. Allies and opponents alike should be aware that the U.S. is willing and able to use the means necessary to defend its national interests. However, the U.S. need not needlessly precipitate a conflict.

  • Reassure South Korea of U.S. resolve. Comments made during the 2016 U.S. presidential campaign exacerbated allied concerns about the willingness of the U.S. to fulfill treaty commitments to defend its allies. The Trump Administration should continue to affirm unequivocal commitment to defending South Korea and Japan, including the threefold U.S. promise of extended deterrence: forward-deployed conventional forces, missile defense, and the nuclear umbrella. At a minimum, the U.S. should pledge to maintain U.S. forward-deployed forces in South Korea and Japan at current levels and augment those forces during a crisis to deter, defend, and defeat security threats in the region.

  • Augment U.S. deterrence capabilities. Washington should explain how reintroduction of tactical nuclear weapons into South Korea and South Korea’s development of an indigenous nuclear weapons program are not viable policies. However, the Trump Administration, in consultation with our allies, should consider the following measures:

  1. Reversing the devastating cuts in the U.S. defense budget by implementing the recommendations in The Heritage Foundation’s 2017 Index of Military U.S. Military Strength;[REF]

  2. Expanding rotational deployments of the 31st Marine Expeditionary Unit from Okinawa to South Korea;

  3. Continuing U.S.–South Korean discussions of augmented rotational deployments of U.S. strategic nuclear-capable assets to northeast Asia, including B-52 and B-2 bombers, carrier battle groups, submarines, and dual-capable aircraft;

  4. Improving allied ballistic missile defense by:
    • Deploying the THAAD missile defense system to South Korea, both to improve protection against the North Korean missile threat and potentially to lengthen the fuse of war by reducing the need for preemptive attack;
    • Urging South Korea to integrate its independent missile defense system into the more comprehensive and effective allied network with the U.S. and Japan;
    • Implementing improvements to U.S. strategic missile defense as separately recommended by The Heritage Foundation.[REF]

  5. Enhancing defense against the North Korean submarine-launched ballistic missile threat by encouraging South Korea to procure and deploy the SM-6 ship-based BMD system and enhancing anti-submarine capacities.

  • Beware the slippery slope of reassurance. Reducing allied doubts about U.S. commitment is a critical, albeit Sisyphean, task. South Korean requests or even demands for U.S. reassurance can seem endless. To date, Washington has already provided: 
  1. A mutual defense treaty,

  2. An extended deterrence guarantee,

  3. Bilateral integrated war plans,

  4. Presidential pledges of commitment during successive Administrations, and

  5. Repeated public affirmations by Secretaries of State and Defense.

Of course, the ultimate symbol of unwavering U.S. commitment is the presence of 28,500 American sons and daughters deployed in harm’s way in South Korea. Yet despite all of these efforts, South Korean officials, legislators, and pundits still call for greater reassurance measures, such as reintroduction of tactical U.S. nuclear weapons, permanent deployment of nuclear-capable strategic assets in South Korea, and greater knowledge of and say in U.S. nuclear strategy.

  • Remember that reassurance is a two-way street. Seoul can and should take certain steps to enhance its own security capabilities. For a number of years, South Korea underfunded its defense budget, and this has led to repeated delays in its planned defense reform. To its credit, Seoul has increased its funding in recent years, but the pace must be maintained over the long term. Steps for South Korea to take toward reassurance include the following:
    1. Improving C4ISR (command, control, communications, computers, intelligence, surveillance, and reconnaissance) capabilities to enable integrated combat capabilities down to the tactical level, an improvement requiring sensors, such as AWACs and high-altitude UAVs, as well as integrated command and communication systems;
    2. Enhancing long-range precision-strike capabilities, including fifth-generation fighter aircraft, attack helicopters, precision-guided munitions, extended-range surface-to-surface missiles, and counterbattery radar and artillery systems;
    3. Accelerating deployment of the THAAD BMD system and more vigorously rebutting inaccuracies put forth by the South Korean media and the Chinese government;
    4. Compartmentalizing difficult historic issues with Japan so as not to continue to impede augmentation of allied defense against common enemies. To this end, Seoul should:  
  • Reassure Washington that the many improvements in allied military capabilities implemented in recent years will not be undone regardless of presidential election outcomes in South Korea. (Progressive candidates have vowed to institute several policies that could strain the alliance.)
  • Fully implement the recently signed General Security of Military Information Agreement that enables more expeditious exchange of information on the North Korea threat during a crisis;
  • Increase the pace and scope of military exercises with Japan and the U.S., including trilateral missile defense, anti-submarine, and mine-clearing operations;


Success in reducing the need for preemptive attack relies on creating more credible deterrence. Chinese strategist Sun Tzu wrote, “To win one hundred victories in one hundred battles is not the acme of skill. To subdue the enemy without fighting is the acme of skill.” The more modern, albeit fictional, strategist Dr. Strangelove commented that deterrence was “the act of producing in the mind of the enemy the fear to attack.” For an opponent to be deterred, the threatened retaliatory response must consist of sufficient military capabilities, unquestioned resolve to respond, and the communication of these capabilities and resolve to the enemy.

Responding to the growing North Korean nuclear and missile threats is like a military version of playing “whack a mole.” Unlike the arcade game, however, the real world holds the very real danger that the mole will whack back.

—Bruce Klingner is a Senior Research Fellow in the Asian Studies Center, of the Kathryn and Shelby Cullom Davis Institute for National Security and Foreign Policy, at The Heritage Foundation.


Bruce Klingner
Bruce Klingner

Senior Research Fellow, Northeast Asia