Nuclear Weapons in the 21st Century

Ages ago, I was a Legislative Assistant on Capitol Hill, working for a member of the House Armed Services Committee. The most impressive person who testified before the Committee was Secretary of Defense James Schlesinger. His mind was like a steel trap. He personified cold logic, equanimity, and mental toughness. I disagreed with almost everything he said about nuclear weapons, but he forced me to rethink my assumptions, sharpen my arguments, and re-do the math, so to speak.

Reading Brad Roberts’s book, The Case for U.S. Nuclear Weapons in the 21st Century (Stanford University Press, 2016) brought me back to those hearings – and forward to the deterrence challenges the United States now faces. Brad writes with authority, having served from 2009-2013 as Deputy Secretary of Defense for Nuclear and Missile Defense Policy in the Office of the Secretary of Defense. And he is downright Schlesingerian in raising questions about Red and Blue “theories of victory” in these troubled times. Arms control wonks willing to have their assumptions and policy preferences challenged would benefit from reading this book.

Brad focuses on the three countries that pose the greatest challenges to nuclear and extended deterrence: Russia, China, and North Korea. He weaves connecting threads around their ambitions to downsize U.S. influence and weaken alliance ties. The “theory of victory” he postulates for each challenger involves bluster, blackmail, and provocations. They all prefer to avoid a direct clash of arms, but if conflict arises, he postulates that the “Red” side is willing to cross the nuclear threshold, in which case the United States will be hard-pressed to succeed. And if the United States does not win, it loses.

While Brad acknowledges that the evidence for his thesis remains inferential and spotty – especially with regard to China – “The United States would be ill served by simply waiting for more evidence” until taking corrective steps. He writes,

“If the United States faces an adversary that believes that limited nuclear war against the United States can be won and thus can be fought, then the United States had better have a theory of victory of its own, one consistent with its interests and those of its allies and embedded in intellectually and politically defensible assumptions.”

This is a tall order, which makes this an ambitious as well as highly contentious book. Brad is up to the challenge of thinking the unthinkable – but only up to a point. Notably missing in his analysis is a defense of the military utility for large numbers of nuclear weapons. Nor does he tackle hard questions relating to the battlefield use of nuclear weapons: How does the United States “win” a limited nuclear war, other than to raise the ante? And what then?

Entering these domains would be redolent of Dr. Strangelove and Herman Kahn’s escalation ladders, which would leave most readers fleeing for the exits. Brad’s defense of over-sized nuclear force structure isn’t based on military utility. Instead, it is based on political or perceptual grounds: that having strategic forces “second to one” would send the wrong signals to Vladimir Putin and U.S. allies in Europe, while reducing U.S. strategic forces within sight of China could encourage Beijing to reach for parity.

The absence of military rationales for the current size of the U.S. arsenal is an indicator of how far we have traveled since the days when Schlesinger, Paul Nitze, Albert Wohlstetter and others postulated theories of victory even in massive nuclear exchanges. Practitioners of nuclear deterrence are still duty-bound to assign mushroom clouds to a few thousand operational warheads on nuclear-weapon delivery systems, but it must be extremely difficult to apply true belief to war plans involving this many detonations. Large targeting sets can only be squared with just war principles of discrimination and proportionality by wearing blinders. Brad doesn’t attempt to do so; his theories of victory are modest, by comparison. His focus is on preventing and, if necessary, limiting the use of nuclear weapons, even though he acknowledges that escalation control and escalation dominance become a cosmic crapshoot once the nuclear threshold is crossed.

Brad does not endorse new, low-yield warhead designs or the reintroduction of tactical nuclear weapons into South Korea, whether for military, political, or perceptual reasons. He does, however, endorse a full-bore recapitalization of the U.S. triad and its appurtenances, forward-deployed missile defenses, proceeding with new dual-capable aircraft, and not pursuing unilateral reductions in force structure as long as Putin’s behavior is so problematic. Other add-ons might be proposed by incoming Trump Administration officials. Pitched battles over earth-penetrating warheads and “robust” national missile defenses may be in the offing.

Brad’s unsettling book asks readers to address hard questions. I give him high marks for doing so. Those seeking an escape from nuclear orthodoxy will be very dissatisfied with this book. But it’s not enough to be dismissive of Brad’s arguments; hard work is needed to deconstruct the military and political rationales for nuclear force structure. The Obama Administration didn’t make much headway in this regard. Instead of pursuing a strategy of substitution to reduce the political utility of nuclear weapons, it chose an additive approach: theater missile defenses and other conventional means were layered on top of deployed or readily deployable nuclear capabilities.

It doesn’t take many nuclear weapons to deter a clear-thinking foe from crossing the nuclear threshold. But a great many nuclear weapons are still presumed necessary to convey messages of resolve and to cover an extremely large number of targets. Deep cuts require not only extending the record of non-battlefield use, but also purposeful strategies to reduce the presumed political utility of nuclear weapons.

Michael Krepon is Co-Founder of the Stimson Center. This piece originally ran in Arms Control Wonk on December 8, 2016.

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