WASHINGTON — Nuclear deterrence is the most important mission for the Defense Department, and the nation cannot afford to let this capability atrophy, the vice chairman of the Joint Chiefs of Staff said here today.

A U.S. Air Force B-2 Spirit Bomber and two F-15 Strike Eagle aircraft fly past spectators during the 2017 Royal International Air Tattoo at RAF Fairford, England, July 16, 2017. The B-2 is a nuclear-capable bomber. Air Force photo by Tech. Sgt. Brian Kimball

Speaking before the Air Force Association’s Mitchell Institute at the Capitol Hill Club, Air Force Gen. Paul J. Selva said that while the instruments of deterrence have changed, the strategy behind it has not.

Maintaining the strategic nuclear deterrence is the No. 1 mission, Selva said. The United States must maintain a healthy nuclear deterrence, he added, because “nuclear weapons pose the only existential threat to the United States of America and our allies.”

“There is no substitute for the prospect of a devastating nuclear response to deter that threat,” the vice chairman said, noting that the U.S. strategic nuclear triad of manned bombers, intercontinental ballistic missiles and submarine-launched missiles complicates the situation any adversary would face in contemplating a preemptive strike.

Reviews in Progress

Selva is in the midst of the Defense Department’s nuclear posture and ballistic missile defense reviews, and while he did not comment on specifics in those efforts, he did say that the nuclear posture review will ensure the United States will maintain its nuclear deterrent securely and reliably. “It will also be tailored to the requirements of the 21st-century world,” the general said.

Everything is on the table in the review, from conservative strategic approaches to radical new approaches, Selva said. “We’re going to find the best set of recommendations to give the president the options to maintain our strategic deterrence against Russia, China and emerging nuclear powers,” he added.

While the means of deterrence has changed over the years, Selva told the forum audience, the philosophy behind it really hasn’t. “Deterrence really is no different in the 21st century than it was in the 20th century or the 19th century or the 1st century B.C. — ‘You hurt me, I’m going to hurt you worse. I have the tools to do it, and if you don’t believe me, then step over the line,’” he said.

“We played these games as kids, but the logic is the same,” he said. “If you attack me, I have the capacity to return that attack, and I will return it with a degree of violence that is commensurate with the violence you’ve done to me. If you can accept that, then we reach a state of equilibrium. It is will, capacity and capability. If you don’t have all of those, deterrence fails.”

Updating the Nuclear Enterprise

Selva said he shies away from using the term “modernization” with regard to the nuclear enterprise. The United States is not rushing to modernize the triad, he said, but the Ohio-class ballistic missile submarines are getting older, the B-52 is a 1950s airframe with capabilities added during its 60-plus-year existence, and Minuteman 3 missiles entered the silos in the 1970s.

The United States will very deliberately replace these systems with newer systems, and just the fact that they are newer will mean there will be additional capabilities, the vice chairman said. He compared the capabilities of his 1970 MG automobile to his 2007 Saturn. “The MG requires a lot of work to run,” he said. The Saturn has six computers, airbags, Global Positioning System and so on,” he said.

Upgrading the nuclear force won’t be cheap, Selva said. “Today we spend roughly 3.5 percent of the defense budget on the ownership and maintenance of our existing nuclear force,” he added, noting that replacement will raise it to just over 6 percent.

Selva was asked about the North Korean nuclear threat. “While it is unclear whether Kim Jong Un can actually target the United States with an intercontinental ballistic missile,” he replied, “it is very clear that he has figured out how to build missiles, and he is willing to proliferate them to any country that will pay for them.”

The North Korean Threat

But even if North Korea cannot target the continental United States, he said, the American nuclear umbrella covers South Korea and Japan. But the North Korean program is shrouded, and much remains unknown.

“Before we can assert Kim Jong Un has a nuclear missile capable of targeting the United States, there are a couple of aspects we must know,” Selva said. “First, he has to have a missile capable of ranging that distance.” U.S. officials believe the recent launches prove he has intercontinental ballistic missile capability.

Second, the North Koreans need to have a guidance-and-control system capable of guiding a rocket over intercontinental distances without breaking up. U.S. officials do not know if Kim Jong Un has that capability.

Third, North Korea also needs to develop a re-entry vehicle that can survive the stresses of an intercontinental missile shot. Once again, U.S. officials do not know if North Korea has this technology.

Finally, the North needs to develop a nuclear weapon that can survive that trip. Again, the United States doesn’t know, Selva said.