The issue of extended deterrence has been in the news a lot in the past few weeks. First, via GSN’s Martin Matishak, at last week’s STRATCOM Deterrence Symposium Brad Roberts, Deputy Assistant Secretary of Defense for Nuclear and Missile Defense Policy, stated:
there will be an increased emphasis [in the Nuclear Posture Review] on extended deterrence and the assurance of allies….”The concern about tipping points is rising,” Roberts said, noting that the anxieties of partner nations in East Asia have “sharpened” as a result of North Korea’s two nuclear tests and the modernization of the Chinese military’s nuclear capabilities.
And yesterday, on the 64th anniversary of the U.S. atomic bomb drop on Hiroshima, Japanese Prime Minister Taro Aso reiterated his nation’s commitment not to pursue nuclear weapons and global nuclear disarmament, while at the same time warning that he considers nuclear abolition to be “unimaginable”. Yukio Hatoyama, the leader of Japan’s primary opposition party took an even stronger pro-disarmament line, noting that “Realizing a nuclear-free world as called for by U.S. President [Barack] Obama is exactly the moral mission of our country as the only atomic-bombed state.” Japan has long been considered to be the most important beneficiary of the U.S. nuclear umbrella.
Those who are wary about reducing the role and size of nuclear weapons in U.S. national security policy are increasingly pointing to the challenges associated with protecting and reassuring allies in an age of Russian aggression, Chinese military modernization, and North Korean and Iranian provocation as a reason why we must be very cautious about further nuclear cuts with Russia, the CTBT, etc.
For example, the bipartisan Congressional Commission on the Strategic Posture of the United States raised a lot of eyebrows in the emphasis it placed on extended deterrence. Take, for example, this graf from the executive summary:
For the deterrence of attacks by regional aggressors and even China, the force structure requirements are relatively modest. The focus on Russia is not because the United States and Russia are enemies; they are not. No one seriously contemplates a direct Russian attack on the United States. Some U.S. allies located closer to Russia, however, are fearful of Russia and its tactical nuclear forces. The imbalance in non-strategic nuclear weapons, which greatly favors Russia, is of rising concern and an illustration of the new challenges of strategic stability as reductions in strategic weapons proceed. The need to reassure U.S. allies and also to hedge against a possible turn for the worse in Russia (or China) points to the fact that the U.S. nuclear posture must be designed to address a very broad set of U.S. objectives, including not just deterrence of enemies in time of crisis and war but also assurance of our allies and dissuasion of potential adversaries. Indeed, the assurance function of the force is as important as ever.[emphasis mine].
Though it didn’t explicitly say so, the Commission implies that extended deterrence is one of the most important, if not the most important, factor driving the size and characteristics of the U.S. nuclear arsenal.
1. So long as U.S. allies could fall victim to nuclear attack, the U.S. should retain nuclear weapons to deter such an attack. However, allied concerns about the state of the U.S. nuclear umbrella should not be taken to mean that they oppose any or even significant changes to U.S. nuclear posture. Rather, key allies such as Japan, South Korea, and Turkey don’t want to be surprised by changes to U.S. strategic posture. They want to be consulted well ahead of time.
2. There is much more to assuring allies than the nuclear component of extended deterrence. For example, a critical factor in an ally’s confidence in the credibility of extended deterrence is its confidence in the strength of its political relationship with the United States. If political relations fray then the credibility of the U.S. extended deterrent will be perceived to be weak, no matter what type of or how many nuclear weapons the United States possesses. Nuclear weapons are often relied on as a crutch to avoid the hard choices and difficult negotiations with allies that changes in U.S. nuclear posture would require.
3. As the Carnegie Endowment’s George Perkovich has noted, there has never been a halcyon day of extended deterrence. On the one hand, some U.S. allies have always feared that the U.S. might bungle its way into a nuclear war. Conversely, there has always been a tension between U.S. alliance commitments and the fears on the part of allies that the U.S. might abandon them. These tensions, however, have not become more pronounced than they were during the Cold War.