Even by the most merciless arithmetic, this triple threat is unnecessary. Congress should take the advice of experts like former Vice Chairman of the Joint Chiefs of Staff James Cartwright and decommission either the bomber or ICBM leg while cutting the forces in the remaining two legs, leaving a deployed warhead total under 500.
The triad's rationale is that diversity of delivery vehicles ensures that the nation's nuclear forces cannot all be wiped out easily, so that enemies can never be certain of avoiding a retaliatory response. But that story is a post hoc rationalization for a force bloated by parochialism between the service branches.
The real reason the triad exists is that the Air Force, having failed to either prevent or control the proliferation of ballistic missile submarines by the early 1970s, coined the term "triad" as part of a marketing effort to protect their bombers. Air Force officials had previously argued that missile submarines weren't necessary to keep the Soviets in check. When the Navy developed nuclear-armed submarines in the late 1950s, its leaders began to question the survivability of bombers and ICBMs.
Chief of Naval Operations Arleigh Burke advocated for "finite deterrence" -- maintaining the smallest arsenal that deterrence requires, by which he meant a system based mostly on submarines. Of the multiplicity of delivery systems, he said, "You very seldom see a cowboy, even in the movies, wearing three guns. Two is enough."
The always-shaky case for the triad has weakened further since the end of the Cold War. Monumental leaps in our ability to precisely aim conventional and nuclear weapons have greatly reduced the number and size of the weapons we need to threaten enemies. And the U.S. military's vast advantage over all rivals makes it even less plausible that we will ever be desperate enough to resort to a nuclear strike.
Meanwhile, targets for our nuclear weapons are disappearing. The new nuclear powers struggle to deploy even a few mid-range delivery vehicles. The Chinese seem uninterested in developing an arsenal that threatens ours; they have built only enough long-range missiles for finite deterrence. And with an economy roughly one-sixth the size of the U.S. and a decaying conventional military, Russia cannot afford nuclear parity. They deploy fewer nuclear weapons than the latest Strategic Arms Reduction Treaty permits, and they are likely to keep shrinking their arsenal if we do, new treaty or not.
Nuclear weapons have also, thankfully, proven irrelevant to modern American wars. The peace among rich states increasingly seems to depend on factors beyond mutual terror. Only poor, threatened states now develop nuclear weapons for security.
These changes also mean that nuclear weapons provide less prestige and budgetary advantage to the military service that owns them. With military budgets under pressure, nukes only compete with conventional programs that service chiefs value more. That's why the Air Force intends to build its next bomber initially without the capacity to carry nuclear bombs -- subtly inviting Congress to get bombers out of the nuclear weapons business. The Navy proposes to operate 10 ballistic missile submarines rather than 14. It may suggest more drastic reform if it cannot move the cost of these boats -- over $5 billion each just for procurement -- off its shipbuilding books and onto a Pentagon-wide account.
Opponents of the triad have the better arguments, but it's the political opportunity created by austerity that may allow them to finally succeed. By increasing pressure on the Pentagon budget, we might induce the military to kill the triad themselves.
Benjamin H. Friedman is a Research Fellow in Defense and Homeland Security Studies and Christopher Preble is Vice President for Defense and Foreign Policy Studies at the Cato Institute.