The latest wave of opposition to the lower-yield W76-2 nuclear warhead the Navy deployed last year crested Wednesday, when five senators asked Secretary of Defense Mark Esper what the Pentagon might use the weapon for, and which civilian nuclear projects had to be postponed to build it.
“It is inconsistent for the United States to begin fielding new nuclear weapons while we urge other countries not to do so, the five senators, four Democrats and an independent who caucuses with Democrats, stated their letter to Esper.
Sen. Dianne Feinstein (D-Calif.), lead signatory on the letter, was joined by: Sen. Patrick Leahy (D-Vt.), vice chair of the Senate Appropriations Committee; Sen. Bernie Sanders (I-Vt.), the progressive firebrand and leading Democratic presidential hopeful; Sen. Tammy Baldwin (D-Wis.), who serves on the Appropriations Committee; and Sen. Elizabeth Warren (D-Mass.), another Armed Services member and contender for the Democratic presidential nomination.
The letter asks Esper to answer five questions. Along with the W76-2’s effect on the pipeline for the National Nuclear Security Administration (NNSA) — the civilian agency pushed the project through while the assembly line at Pantex was still rolling from the life extension for the W76-1 warhead — the senators want to know whether strategic delivery systems carrying the weapon would be counted against limits set under the New START treaty.
Like the W76-1, W76-2 is used on Trident II D5 missiles carried aboard Ohio-class ballistic missile submarines, which are covered by the accord between Russia and the U.S. The treaty will expire in less than a year unless President Donald Trump and Russian President Vladimir Putin agree to an authorized extension of up to five years.
The treaty limits Moscow and Washington to no more than 1,550 warheads across 700 intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers. The senators called on Esper to make the case to Trump for extending New START.
The Pentagon confirmed this month that it deployed the w76-2 in December 2019. The nonprofit Federation of American Scientists estimates the weapon has a yield of roughly 6 kilotons or so, compared with around 100 kilotons for the W76-1.
The NNSA spent roughly $75 million on W76-2 in fiscal years 2019 and 2020 and plans to wrap up work associated with the lower-yield weapon before the current fiscal year ends Sept. 30.
