The president claims it’s a new weapon, but it’s probably just a neutered version of a warhead that’s been around for decades.
By Kyle Mizokami SEP 10, 2020
In a series of interviews, President Donald Trump told Bob Woodward that he had built a new nuclear weapon system “nobody’s ever had.” However, the complexity of nuclear weapon design makes it virtually impossible for a new nuclear weapon system to have been developed in just three years.
Trump made the comments during interviews conducted for Woodward’s new book, Rage. In interview excerpts published by The Washington Post, the president bragged to the bestselling author and two-time Pulitzer winner:
“I have built a nuclear—a weapons system that nobody’s ever had in this country before. We have stuff that you haven’t even seen or heard about. We have stuff that Putin and Xi have never heard about before. There’s nobody—what we have is incredible.”
The statement was a curious one, as the federal government has neither made an announcement it is developing a new nuke nor sought funding to make one a reality. Nuclear weapons are enormously difficult and expensive to develop, and a new nuke would probably take the better part of a decade—or more—to go from the drafting table to sitting in a silo or bomb bay.
So what was Trump talking about? The president was likely alluding to the W76-2, a new nuclear warhead designed to fit on the U.S. Navy’s Trident D-5 submarine-launched ballistic missiles.
The U.S. Navy currently fields 12 nuclear-powered ballistic missile submarines, each equipped with approximately 20 Trident D-5 submarine launched missiles. Each D-5 carries between four and five W-76 warheads each. The W-76 has an explosive yield of approximately 100 kilotons, or about six times the power of the bomb dropped on Hiroshima. With a range of 4,600 miles, a U.S. missile submarine parked off the coast of Canada could rain up to 80-100 warheads on western Russia.
The W76-2 was first mentioned by the Trump Administration in February 2018 as a weapon to “help counter any mistaken perception of an exploitable ‘gap’ in U.S. regional deterrence capabilities.” Military planners worried that the U.S. did not have a small, low-yield tactical nuclear weapon that could quickly respond to a Russian low-yield nuclear strike. America’s tactical nuclear weapons are restricted to airplane-delivered nuclear gravity bombs that could take hours to prepare and deploy. A Trident D-5 could deliver a low-yield weapon like the W76-2 in a matter of minutes, streaking past the enemy’s air defenses to virtually guarantee delivery.
Thermonuclear weapons like the W76-2 are designed to utilize two stages—primary and secondary—to achieve their advertised explosive yields. The primary fission stage is a low-yield nuclear weapon that then triggers the secondary stage, which sets off a much, much larger fusion explosion. The National Nuclear Security Agency has explained the W76-2 is simply a W76 configured for “primary-only detonation.” Nobody outside of the U.S. government is really sure how small the W76’s primary stage is, but it is likely between 4 and 10 kilotons, or 4,000 to 10,000 tons of TNT. The Federation of American Scientists (FAS) estimates the primary stage yield at five kilotons.
The W76-2 is simply a neutered W76 and, as a result, was relatively easy to develop. The weapon was deployed in late 2019 aboard the missile submarine USS Tennessee (see top). FAS estimates the U.S. government rebuilt 50 W76s to W76-2 configuration, and it’s likely that every missile submarine carries one or two missiles exclusively armed with them on every patrol.
Trump describes the W76-2 as a weapon “nobody’s ever had.” Yet the actual need for the W76-2 is heavily disputed outside of government, with many observers believing the weapon is unnecessary and dangerous. The Union of Concerned Scientists believes that an adversary would be able to detect the launch of a Trident D-5, but would not know if the warhead was the W76-2 or the vastly more powerful W76. The new warhead could thus blur the lines between battlefield and all-out nuclear warfare.
To the President’s credit he did not describe “his” new weapon as new, or exotic, or claim that it’s a capability that doesn’t exist anywhere else. As for his statement that the U.S. military has weapons “that you haven’t even seen or heard about”—we don’t have a clue what those are, but they almost certainly do exist.