After over a decade of being free of nuclear-weapons, UK will host US-made B61-12 nuclear bombs on British soil.

Prime Minister Keir Starmer announced the deal on the sidelines of the NATO summit at the Hague. UK will also obtain a squadron of F-35 fighter jets that are capable of carrying the gravity bombs.

The B61-12 is the latest variant of the B61 family of air-launched nuclear gravity bombs, which have been operational with the US military since 1968.

The B61-12 has a length of 12 ft and weighs approximately 825 lb. It can be delivered to the target in either ballistic gravity or guided drop modes.

The B61-12 is an enhanced version of the B61-4 warhead and boasts two main assemblies: the bomb assembly and the tail kit guidance assembly.

The bomb assembly comprises reused, refurbished, and the latest nuclear and non-nuclear components.

The new tail kit assembly combines new guided free-fall capability for precision strike, with the existing ballistic delivery capability of the B61 bomb.

The B61-12 has both air- and ground-burst capability. Reports suggest that it's ground penetration is comparable to the GBU-57 bunker buster bombs.

The bomb can be air-launched by aircraft platforms such as the B-2A, F-15E, F-16C/D, F-16 MLU, PA-200 and B-21.

Notably, the F-35 was certified to carry the B61-12 thermonuclear gravity bomb in March 2024. This was the first time a stealth jet was capable of carrying both nuclear and conventional weapons.

The F-35 can carry two B61-12s internally and use its suite of ground-scanning sensors and data links to target the bomb more precisely than other B61-delivering aircraft.

The F-35's stealth and radar-evading capabilities make it the most effective jet to deliver strategic nuclear gravity bombs.

The F-35 has dramatically greater odds of both reaching its target to deliver a gravity bomb and returning to base than a non-stealth fighter.

Notably, the UK already possesses Trident as a nuclear deterrent of last resort. The UK keeps a single submarine at sea at all times. It carries over 40 warheads, each with a destructive power about six times that of the Hiroshima bomb.

Theoretically, the Trident nuclear programme can destroy major cities such as Moscow or Beijing.

But military planners have suggested a need for lesser tactical or sub-strategic nuclear weapons that could be used on the battlefield and have a localized impact.

The weapon of choice for such strategic use is the B61-12. This simple gravity bomb must be flown and delivered directly to its target.

Even though the full details of the military purchase are not known, it is estimated that the deal will cost the UK over £900 million, with additional costs for refurbishing storage vaults at the Royal Air Force base at Marham -- where the bombs are likely to be stationed.

Additionally, under the ‘nuclear sharing’ agreement within NATO, the B61-12 bombs will remain under US custody, although on British soil.

UK will need the US president’s permission to use the nukes. The F-35 jets, on the other hand, will be owned by the British government.

Reports suggest that Starmer rushed the deal without any parliamentary debate or vote. Critics claim the decision goes against the country’s democratic values and undermines British sovereignty.

Though the purchase might help Britain gain a strategic edge in unforeseen times of crisis, Starmer appears to have a strong battle ahead to calm his critics.

b61-12 thermonuclear gravity bomb

UK to host US-made B61-12 nuclear bombs under NATO strategic deal: Specifications, precision & range

b61-12 thermonuclear gravity bomb

UK to host US-made B61-12 nuclear bombs under NATO strategic deal: Specifications, precision & range