Brad Roberts on Extended Deterrence I : Nuclear "Tailoring"



The Graduate School at UCSD recently hosted Brad Roberts, who served in the Obama administration as Deputy Assistant Secretary of Defense for Nuclear and Missile Defense Policy until early 2013. He directed us to a paper he had written for Japan's National Institute of Defense Studies on extended deterrence in Northeast Asia (see our reflections on this issue here and here). Although written for a Japanese audience, it provides an excellent primer on the issue. It also contains interesting insight into the Obama administration’s policy toward the region and elements of the pivot that have not received the public attention they deserve.

Roberts nests the discussion in the context of Chinese force modernization—including with respect to nuclear weapons—and walks through the risks of a nuclear North Korea. Some of these risks—such as a bolt from the blue—are exaggerated in our view but the effects of the “stability-instability paradox” cannot be ruled out: that Pyongyang’s deterrent may either encourage provocation or generate miscalculation.

Running through Roberts’ analysis is clearly a second problem that motivated the pivot: that allies both in Asia and elsewhere needed reassurance with respect to US alliance commitments. Roberts does not address at length the sources of this anxiety, but they range from fears about the policy priorities of a Democratic president, to the larger policy dysfunction in Washington, to the Prague speech on nuclear weapons, to deeper concerns about declining American capabilities and increasing fiscal constraints.

Whatever the source of these worries, the Obama administration responded by forming both an Extended Deterrence Dialogue with Japan and an Extended Deterrence Policy Committee with Korea in 2010. Given that the US rejects a “mutual vulnerability” approach to deterrence vis-à-vis North Korea and Iran and that strategic nuclear weapons use is in any case not credible, such reassurances involve a complex layered approach. Today, we take up the question of the “tailoring” of the nuclear umbrella; tomorrow we look at the strategic logic of missile defenses.

The Obama administration’s policy on these questions is spelled out in three early strategic policy reviews: the 2010 Quadrennial Defense Review, the Nuclear Posture Review, and the Ballistic Missile Defense Review. With respect to declaratory policy, nuclear tailoring arises from a rejection—or at least postponement--of the idea that the “sole purpose” of nuclear weapons is deterring nuclear attack on the United States or its allies. Rather, US policy specifies a continued role for U.S. nuclear weapons in deterring conventional attacks. (The Obama administration also explicitly modified the negative security assurance to allies to stipulate that countries like North Korea and Iran are objects of U.S. deterrence planning, a signal that the North Koreans have not missed).

At the operational level, the strategy of “tailoring” has been signaled by a renewed commitment—budgetary constraints permitting—to modernization of the fighter-bomber fleet capable of carrying "non-strategic" nuclear weapons; in fact, it is not clear that there is such a thing as a "non-strategic nuclear weapon" and the weapons themselves are actually the same. According to Roberts, tailoring was necessitated by the retirement of the nuclear-armed Tomahawk cruise missile, an apparently small change that had the effect of eliminating the one "non-strategic" nuclear weapon available for use in the region.

Is more needed? Posing the question raises important issues about what Japan might be called on to do, and how those actions might be seen elsewhere in the region. Japan’s three no’s--non-possession, non-production, and non-introduction of nuclear weapons—have played a crucial assurance function for the rest of the region. Do we really want to modify them? And what are the alternatives?

The current East Asian model relies on the U.S. nuclear triad of strategic delivery systems. In crises, U.S. commitment can be signaled by changing alert levels and deploying nuclear-capable bombers, as was done in March 2013 during the times of troubles following the North Korean nuclear test (we thought that move was gratuitous). Now, both the Abe administration and some American nuclear strategists are thinking about subtle modifications: to allow future nuclear-capable deployments to the region under certain specified conditions; improving U.S. military infrastructure on Guam to enable deployments of dual-capable U.S. aircraft; even creation of NATO-like nuclear consultative mechanisms.

All of these strike us as higher-risk than they look, signaling quite fundamental shifts in Japanese grand strategy. Roberts reminds us of the tradeoffs by putting them in the context of alternatives that are even more implausible for the region. One would be to return to a Cold War model in which the triad was supplemented by the deployment of "tactical" nuclear weapons in South Korea and aboard U.S. naval surface combatants (again, if you believe that the strategic-tactical distinction makes sense). A handful of right-wing politicians in South Korea have vetted this idea--Toby Dalton and Yoon Ho Jin provide an introduction at the Asia Times. This is not going to happen and Roberts explains patiently why it is such a bad idea: “doing so would significantly erode the political pressure on North Korea to denuclearize, increase nuclear targeting of South Korea by the North, and add little to either the deterrence of the North or the assurance of the South.”

Other nuclear strategists have talked about the European or NATO model, in which nuclear policy is coordinated by defense ministers through the Nuclear Planning Group (minus France, who did not re-join the NPG when it re-joined the alliance in 2009). Under this model, the United States forward deploys nuclear weapons and operates dual-capable aircraft with select NATO partners. But the political foundation of this model is rooted in the presence of nuclear capable states—Britain and France—and the historical legacy of deployments designed to offset perceived Soviet conventional superiority. It strikes us even more risky to institutionalize Japan’s or South Korea’s role in US nuclear posture in the region.

Providing assurances to allies is important, but not only for the credibility of the deterrent; limits on our own allies’ nuclear ambitions have been a core component of US policy toward the region. In providing assurances it is important to also not be held hostage by those who want to push the edge of existing capabilities in ways that could severely complicate regional politics. In the end, China’s grand strategy will be crucial in this regard: Beijing could be a lot more thoughtful about the effects of its current buildup and force deployments, particularly with respect to Japan.

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