The National Nuclear Security Administration could probably whip up a new low-yield warhead for submarine-launched ballistic missiles in “a couple years,” but doing so would slow ongoing programs to extend the life of current U.S. warheads, a former National Security Council official said Tuesday.

“That’s something that the laboratories probably effectuate in a relatively short period of time, a couple of years,” Jon Wolfsthal, senior director for arms control and nonproliferation in the Obama administration’s NSC, said at a press event hosted by the Arms Control Association. “It depends on how they want to affect the throughput of all the other life-extension programs that are currently underway.”logo-nnsa-top

Those encompass updates for the W88 and W76 used on submarine-launched ballistic missiles, the W80 used on air-launched cruise missiles, and the B61 gravity bomb.

Introducing a new warhead into the mix, as a leaked draft of the Donald Trump administration’s Nuclear Posture Review recommends, “would throw off some of the schedules,” Wolfstahl said.

Wolfsthal was one of three panelists — all former government officials now working for nonproliferation-focused nonprofits in Washington — who spoke and answered questions from the audience during the 90-minute briefing.

The proposed low-yield submarine-launched warhead would be made from parts of existing weapons. The draft report also proposed studying whether the U.S. should build an entirely new submarine-launched cruise missile, along with a new warhead for the weapon.

Another panelist said modifying existing warheads would be comparatively simple, compared with the massive and disruptive undertaking of creating an entirely new warhead.

It would take “a relatively modest but not trivial modification to an existing weapon to convert your SLBM [submarine launched ballistic missile] weapon to be one that’s low-yield in the near term,” said Joan Rohlfing, president and chief operating officer of the Washington-based Nuclear Threat Initiative.

Rohlfing dismissed the idea that either submarine-launched missile discussed in the Nuclear Posture Review was cooked up by NNSA in an attempt at mission creep.

The weapons’ inclusion was more likely political, Rohlfing said, intended as a response to Russia’s supposed escalate to de-escalate strategy. According to that doctrine, Moscow would quickly nuke its way out of any armed conflict it could not win with conventional weapons.