Air Force Gen. Mark Welsh, outgoing chief of staff, said Wednesday that each leg of the U.S. nuclear triad will remain critical for strategic deterrence regardless of budget pressures, and that a separate account to fund the nuclear forces modernization for all three legs is worth considering.

“I’m a believer in the triad,” Welsh, who is retiring from his position July 1, told a group of reporters at a Defense Writers Group breakfast. “I believe that the benefits you get from having a very survivable capability, like the [submarine]-launched ballistic missile; a very flexible option, like a bomber; and a very responsive option, and relatively cheap option compared to the others, like the ICBM, is actually a good approach to provide strategic deterrence.”

Air Force Chief of Staff Gen. Mark Welsh. Photo: U.S. Air Force.
Air Force Chief of Staff Gen. Mark Welsh. Photo: U.S. Air Force.

A constrained defense budget and the expected $350 billion price tag for modernization of the U.S. nuclear arsenal over the next decade have led Pentagon officials to suggest that the Defense Department will eventually make trade-offs between updates to nuclear and conventional weapons programs.

This could mean changes or cuts to major programs or, although unlikely, even the elimination of an entire leg of the nuclear triad. Suggestions over the years have included stripping strategic bombers of their nuclear mission or entirely eliminating ICBMs, for instance, largely to save costs.

Welsh argued, however, that all three legs are necessary from an operational standpoint: strategic bombers because of their recall capability, ballistic missile submarines due to their survivability, and ICBMs because they are always on alert–in addition to being the least costly of the three legs.

Asked about the circumstances under which the Defense Department might consider moving from a triad to a dyad, Welsh said this could only happen “if resources really collapse and we have no way of modernizing anything.”

“If you’re going to have a capability, it’s got to be capable, credible, and viable, and if it isn’t, it’s not really a capability,” he said. These requirements must be maintained throughout modernization of the nuclear enterprise – which includes the Pentagon’s delivery systems in addition to nuclear warheads maintained by the National Nuclear Security Administration – and would not necessarily work under a dyad, he said.

“I think you’re limited with a dyad versus a triad,” he said. Cost savings, not military reasons, would prompt any consideration of this change, he said. “As a military guy I’m always going to say the triad’s the answer. Anything else, you’re settling for some other reason.”

Air Force officials have indicated in recent months that they would welcome a strategic deterrence fund separate from the agency’s topline budget, similar to the National Sea-Based Deterrence Fund given to the Navy for the replacement of Ohio-class nuclear submarines.

Air Force Secretary Deborah Lee James told lawmakers in March to consider a fund for all three legs of the triad, which would include the Air Force’s upcoming Ground-Based Strategic Deterrent meant to replace aging Minuteman III ICBMs, and the new B-21 bomber.

“I do believe that if the nation’s going to have a debate about the future of the nuclear business, then the debate must include all pieces of the nuclear business,” Welsh said. “So if you have funding that’s set aside for one piece, it makes sense to have funding set aside for the entire enterprise.”

Welsh also indicated that the future of strategic deterrence may be subject to change if the U.S. pursues new deterrent capabilities to address the threat posed by terrorists. “Is it nuclear, is it cyber, is it a blended capability across multiple lines?” he said.