The U.S. military will develop a new, higher-yield variant of the B61-12 nuclear gravity bomb designed for delivery by modern aircraft, the Pentagon announced on Oct. 27.
Designated the B61-13, the new bomb will be suited for use against hardened and large-area military targets, the Defense Department said in a statement. Congressional approval and funding is needed before development of the bomb can begin.
The National Nuclear Security Administration will produce the B61-13, which would replace some of the B61-7s in the current nuclear stockpile and have a yield similar to the B61-7, which is higher than that of the B61-12, the Pentagon said.
“Today’s announcement is reflective of a changing security environment and growing threats from potential adversaries,” said Assistant Secretary of Defense for Space Policy John Plumb. “The United States has a responsibility to continue to assess and field the capabilities we need to credibly deter and, if necessary, respond to strategic attacks, and assure our allies.”
The NNSA completed its first war-ready B61-12 in November 2021, though that was about a year late. The nonprofit Federation of American Scientists estimated the agency would build 480 of the bombs through fiscal year 2026. The bomb hit full-rate production in June 2022 and deliveries to the Air Force for use aboard the F-35A are underway.
The decision to build a new B61 variant, made in close collaboration with the NNSA, took into account military requirements for dealing with a “rapidly evolving security environment” as laid out in the 2022 Nuclear Posture Review, though it is not in response to any specific current event, the Pentagon said. U.S. peer competitors continue to expand, diversify, and modernize their nuclear forces while increasing reliance on nuclear weapons, the review says.
“The B61-13 represents a reasonable step to manage the challenges of a highly dynamic security environment,” said Plumb. “While it provides us with additional flexibility, production of the B61-13 will not increase the overall number of weapons in our nuclear stockpile.”
The B61-13 would take advantage of the current, established production capabilities supporting the B61-12, and would include the modern safety, security, and accuracy features of the B61-12, the Pentagon said. Once it goes into production, the B61-13 will be a one-to-one replacement for the B61-12, keeping the stockpile at current levels, the Pentagon said.
The Air Force has integrated the B61-12 on several carrier aircraft including versions of the B-2 bomber, the F-15, F-16, F-35 and has plans to carry it onboard the in-development B-21 stealth bomber.