B61-12

The B61-12 is the latest variant in the B61 family of U.S. air-delivered thermonuclear gravity bombs, first fielded by the National Nuclear Security Administration (NNSA) in late 2021 after a Life Extension Program (LEP) that began in 2012. It consolidates four older B61 variants (Mods 3, 4, 7, and 10) into a single weapon, extending the design's service life by roughly 20 years.

Technically, the B61-12 pairs a refurbished nuclear physics package with a new Boeing-built guided tail kit assembly (TKA), giving it a degree of precision previously absent from U.S. gravity bombs. Its yield is dial-a-yield, reportedly selectable across four options up to roughly 50 kilotons. Because accuracy improves substantially with the tail kit, analysts such as those at the Federation of American Scientists have argued the weapon offers greater military utility at lower yields, raising debates about lowered nuclear thresholds.

The B61-12 is certified for delivery by several dual-capable aircraft (DCA), including the F-15E, F-16, B-2, and the F-35A, with PA-200 Tornado and Eurofighter integration relevant to NATO allies. It is central to NATO nuclear sharing arrangements, under which U.S. weapons are forward-deployed in Belgium, Germany, Italy, the Netherlands, and Türkiye and would, in wartime, be delivered by host-nation aircraft.

Deployment to European bases reportedly accelerated in late 2022, drawing criticism from Russia and arms-control advocates who argue it undermines the spirit of the Non-Proliferation Treaty (NPT) Articles I and II, though the United States and NATO maintain the arrangements predate and are compatible with the treaty. The weapon's full production run is expected to conclude in the mid-2020s, with total program costs estimated by the Government Accountability Office at well over $10 billion. For MUN delegates, the B61-12 frequently surfaces in First Committee (DISEC) debates on disarmament, tactical nuclear weapons, and NATO–Russia strategic stability.