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Conclusion: The North Korean Crisis and the Second Nuclear Age

Aaron L. Friedberg

PDF free through October 1, 2017

Like its predecessor, the second nuclear age has unfolded more slowly than some had expected and many had feared. Since India and Pakistan conducted their multiple, parallel tests in 1998, three aspiring nuclear weapons states—Iraq, Libya, and Syria—have been removed from contention by force or coercion. Another—Iran—has agreed under diplomatic, economic, and military pressure to suspend its efforts, at least for now. Only North Korea has thus far succeeded in crossing the nuclear finish line, despite U.S.-led efforts to prevent it. To date, the post–Cold War flow of new nuclear weapons states has come in drops rather than a sudden cascade.

North Korea’s progress in expanding and perfecting its arsenal, on the other hand, has been surprisingly rapid. Following its initial, and by most accounts only partially successful, detonation of a fission device in 2006, Pyongyang pressed ahead with a series of weapons tests and with the development of a variety of increasingly long-range delivery vehicles. If it has not already done so, the North is generally assumed to be close to perfecting the techniques necessary to build small, light warheads of significant yield, and it will soon be able to put them on solid-fueled ballistic missiles capable of striking targets at increasing range. In July 2017, U.S. officials reported that Pyongyang had conducted its first successful test of an intercontinental ballistic missile. Depending on the capacity of its plutonium-reprocessing and uranium-enrichment facilities, the North could have enough fissile material to build an arsenal of as many as 80 weapons by 2020. After an interval of inaction and “strategic patience” under the Obama administration, these developments are stirring a new sense of urgency in Washington and across Northeast Asia.

Most of the essays in this report proceed from the assumption that, despite the growing threat they pose, North Korea’s nuclear weapon and missile programs cannot be stopped or rolled back. Unfortunately, the history of the last two decades provides little reason for optimism on this score. All the factors that have conspired to enable Pyongyang to reach this point still seem to be in place. Like his father, Kim Jong-un appears to regard nuclear weapons as the best available tool with which to deter an attack and extract concessions from other nations, and as the ultimate guarantor of his personal safety. No package of benefits—neither economic assistance, nor diplomatic recognition, nor paper promises of security—will be sufficient to persuade him otherwise.

The only scenario in which Kim might conceivably agree to part with his nuclear weapons would be if he were faced with the certainty of his own imminent demise. A credible threat to this effect has sadly proved difficult to arrange. Despite some tough talk from President Donald Trump, the United States and South Korea still lack an effective answer to the North’s non-nuclear counter-deterrent—its ability to rain death and destruction on Seoul using artillery, special forces, and perhaps chemical and biological weapons in response to a preemptive strike on its nuclear forces. Even if U.S. and South Korean decision-makers were willing to take this risk, Pyongyang’s long-standing strengths in tunneling and deception, and its imminent deployment of multiple mobile missile launchers, would make a “splendid,” disarming preemptive strike with conventional weapons extremely difficult to carry off and impossible for military planners to promise with assurance in advance.

This leaves only the threat of economic strangulation through sanctions far more stringent than any that have yet been imposed, including tight constraints on commercial trade, imports of critical foreign-manufactured components essential to North Korea’s weapons programs, the “illicit activities” (including drug running and counterfeiting) that earn the regime hard currency, and the financial institutions through which dollars flow in and out of the country. Here the key player is China. Despite its protestations to the contrary, Beijing could effectively cut Pyongyang off from the world, perhaps bringing the regime to its knees. The Trump administration has sought to cajole or coerce China into taking more aggressive steps, hinting that it might be preparing to take military action and imposing some preliminary sanctions on a Chinese bank accused of assisting the North. [1] But Beijing has thus far refused to budge, presumably for fear of causing the regime to collapse, unleashing a flood of refugees, and perhaps leaving a unified democratic and U.S.-allied state on its border. In the past, China has also found the North Korean nuclear issue, and the promise that it would somehow help resolve this problem, to be a useful source of leverage in its dealings with the United States.

Recent statements from semi-official sources hint that Beijing might be willing at some point to tighten sanctions on the North, perhaps if it detonates another nuclear weapon. [2] If China could be persuaded to act, and if Pyongyang can be deterred from proceeding, it is conceivable that the maturation of its programs could at least be slowed. Whether such a ploy would work (and for how long), what Beijing would demand for its services, and whether Washington would be willing to pay this price all remain to be seen.

Assuming that the North retains and continues to improve its nuclear-strike capabilities, how should the United States and its allies respond, and what are likely to be the implications, both for regional stability and for the subsequent unfolding of the second nuclear age? The allied response to the evolving nuclear threat will clearly involve some mix of defensive and deterrent measures. The deployment of the Terminal High Altitude Area Defense (THAAD) anti-ballistic missile system to South Korea and the ongoing strengthening of U.S. and Japanese land- and sea-based missile defenses can help reduce the North’s confidence in its ability to strike its enemies. These measures also may cause the regime to expend additional resources on building more weapons and developing decoys or maneuvering re-entry vehicles to increase the odds that at least some warheads will reach their targets.

U.S. and South Korean conventional forces have sufficient fighting power to overwhelm their opposition, invade the North, topple the Kim regime, and reunite the Korean Peninsula. In order to deter Pyongyang from using its growing nuclear arsenal, and to defeat it if it does, the United States, in conjunction with its allies, will also need to re-examine its own capabilities and plans for conducting limited nuclear operations. As Michito Tsuruoka points out, this may require the development of new systems to supplement the relatively small number of aging B61 gravity bombs remaining in the U.S. arsenal.

But are stronger defenses and a more credible deterrent sufficient for dealing with a leader like Kim Jong-un? Even a very good missile defense system can be overwhelmed or defeated, and if just a single warhead gets through, the consequences would be catastrophic. The certain knowledge that the United States will avenge their deaths with a crushing retaliatory blow is hardly reassuring to the potential victims of a North Korean nuclear first strike. For these reasons, as Matthew Kroenig notes and as Sugio Takahashi discusses at length, the United States, and perhaps its allies as well, may need to prepare to preempt such an attack. According to Takahashi, in the event of a severe crisis on the Korean Peninsula, Tokyo may need to be persuaded that the United States possesses such a capability and is willing to use it at the first sign of an impending North Korean strike before Japan agrees to allow U.S. forces to operate from bases on its territory. Takahashi strongly implies that the United States may even have to make clear that it is willing to use nuclear weapons (“the promptest and surest means”) to disarm the North. This proposal and the issues it raises demand further discussion, not only between Washington and Tokyo but with Seoul as well.

If Kim succeeds in fending off international pressure and continues to improve and expand his nuclear forces, he will likely feel emboldened to engage in yet more threatening and provocative behavior against North Korea’s neighbors. Safe behind his nuclear shield, Kim will demand economic benefits and shows of respect, and he may even entertain renewed hopes of somehow achieving eventual forced reunification with the South. Provided that nothing happens in the near term to shake their confidence in U.S. security guarantees, neither Tokyo nor Seoul will make any sudden moves toward acquiring their own nuclear weapons. But further unchecked development of North Korea’s capabilities, and the visible failure of yet another round of U.S.-led efforts to stop them, will lend urgency to the quiet discussions of this eventuality that are already underway in both capitals.

Beyond the Korean Peninsula, Pyongyang’s successful defiance of the United States will inspire others to believe that, with the right combination of audacity and subterfuge, they can do the same. The lessons that Tehran may draw from this drama are especially troubling. Meanwhile, the North’s growing stockpile of fissile material and its increasing expertise in the design and manufacture of weapons and delivery systems will raise the risk of onward proliferation to other states and possibly even to nonstate actors. The second nuclear age is just getting started.

Aaron L. Friedberg is Professor of Politics and International Affairs at Princeton University and a Counselor to the National Bureau of Asian Research.


[1] Alan Rappeport, “U.S. Imposes New Sanctions over North Korea Ties,” New York Times, June 29, 2017.

[2] According to the Global Times, “China will not remain indifferent to Pyongyang’s aggravating violation” of existing UN Security Council resolutions prohibiting further weapons tests. The article claims that “more and more Chinese support the view that the government should enhance sanctions over Pyongyang’s nuclear activities. If the North makes another provocative move…the Chinese society will be willing to see the UNSC adopt severe restrictive measures that have never been seen before, such as restricting oil imports to the North.” “Is North Korea Nuclear Crisis Reaching a Showdown?” Global Times, April 12, 2017,