10/04/2013 04:06 pm ET Updated Jan 23, 2014

Shutting Down Nukes: Who Needs a Triad?

For half a century the conventional wisdom on U.S. nuclear policy has been that not only does the United States need thousands of nuclear weapons, but that they must be based on three distinct types of delivery vehicles: long-range bombers, intercontinental ballistic missiles (ICBMs), and submarine-launched ballistic missiles (SLBMs). The warheads and delivery vehicles that provide the capability to launch nuclear weapons from land, sea and air are referred to as the nuclear triad -- the nuclear theorists' version of the holy trinity. For most of the past 50 years any suggestion that the nation might be able to maintain its security while getting rid of one or more legs of the triad has been considered blasphemy.

But a new report by the Cato Institute -- "The End of Overkill: Reassessing U.S. Nuclear Weapons Policy" -- reminds us that the concept of the triad is far from sacred. It was cobbled together in the late 1950s and early 1960s in part in order to give each of the three military services -- Air Force, Army and Navy -- a piece of the nuclear action, and, most importantly, of the resources that go along with it.

Rationales for maintaining a three-legged nuclear deterrent soon followed, building on the different characteristics of each type of nuclear delivery vehicle. But as the Cato report notes, the case for a triad was never air-tight. The arguments in favor of a triad were grounded in two propositions. First, the U.S. needed a "diversity of delivery systems" to protect against a preemptive attack by the Soviet Union. The idea was that Moscow could never be assured of taking out all U.S. bombers, ICBMs, and ballistic missile submarines in one fell swoop; therefore the leaders in the Kremlin would not dare launch a first strike against the United States. Second, U.S. policymakers believed that the United States needed the ability to wipe out Soviet nuclear forces as a way to deter Moscow from invading Western Europe.

These propositions were dubious even during the Cold War. They make absolutely no sense now. The Soviet Union was never close to having a capability to preemptively destroy the U.S. nuclear arsenal, nor was it chomping at the bit to start a war in Europe. Possessing nuclear weapons was a protection against being attacked with nuclear weapons by the other side, but playing with the notion of a first strike posed the risk of miscalculation leading to a nuclear war -- with one side shooting off its nuclear weapons in fear that they might otherwise be eliminated in a disarming first strike by the other.

Fast forward to the 2000s, and the triad concept has little to recommend it. Neither Russia nor any other nuclear-armed power has the capability to destroy U.S. ballistic missile submarines, and, as Cato suggests, if any nation were to make progress in that direction there would be plenty of time for the United States to adjust its forces accordingly. And I can envision no scenario in which a preemptive attack on another country using nuclear weapons would be anything but a catastrophe of historic proportions.

Given these realities, Cato suggests restructuring U.S. nuclear forces around ballistic missile submarines, while eliminating both ICBMs and nuclear-armed bombers. The Cato analysis suggests that not only would this approach be sound defense doctrine, but it would save about $20 billion a year in a time of tight budgets, according to a rough calculation based on the Stimson Center's estimate of the total costs of the U.S. nuclear arsenal.

No one in a position to make the decision will cast aside the triad tomorrow, or the day after, but doing so should become a serious part of the discussion of how best to reduce, and ultimately eliminate, nuclear weapons.

The last time there was anything approaching serious consideration of getting rid of the triad one of the people involved was none other than Ashton Carter, the Obama administration's Deputy Secretary of Defense. As an Assistant Secretary of Defense for International Security Policy during the Clinton administration, Carter was tasked with reassessing the role of nuclear weapons in U.S. policy in a post-Cold War environment as part of the first Nuclear Posture Review (NPR). He duly considered the subject, convened task forces to explore it, and came up with a recommendation for a "monad" built around as few as 10 Trident submarines with 24 submarine-launched ballistic missiles in each. Carter's proposal generated a strong backlash from defenders of the triad, and never gained traction. But at the beginning of a new era in which U.S. strategy must be modified to adapt to the realities of reduced resources and a rapidly changing strategic landscape, Carter's proposal to get rid of the triad deserves a second look. Cato's new report makes a strong case for doing so.

William D. Hartung is the director of the Arms and Security Project at the Center for International Policy and the author of Prophets of War: Lockheed Martin and the Making of the Military-Industrial Complex (Nation Books).