US nuclear weapons return to UK after 17 years: What it signals for NATO and Russia | Explained

Two B61-12 joint test assembly units are prepared for shipping at the Weapon Modernization Lab at Sandia National Laboratories. (Photo Credit: Craig Fritz)

For the first time since 2008, the United States is believed to have redeployed nuclear weapons to Britain, a development that could reshape NATO’s nuclear posture in Europe. Evidence gathered from open-source flight tracking, defence experts, and Pentagon planning documents suggests that the US delivered B61-12 thermonuclear bombs to RAF Lakenheath in Suffolk earlier this month, Bloomberg reported.

On July 16, observers recorded an unusual movement: a US Air Force C-17 Globemaster transport aircraft departed from Kirtland Air Force Base in Albuquerque, New Mexico -- the US military’s principal nuclear weapons hub -- and flew directly to Lakenheath. What made the mission stand out was that the plane’s transponder remained switched on, broadcasting its identity and location for all to see.

The aircraft was part of the Prime Nuclear Airlift Force, a specialised unit responsible for moving nuclear weapons. Such missions are typically shrouded in secrecy, but this flight left an unmistakable trail.

Defence analyst William Alberque, a senior fellow at the Pacific Forum, told Bloomberg, “This is a down payment that there’s more to come on shifting NATO’s deterrence posture toward strengthening. Returning US nuclear weapons to the UK is no small feat.”

The flight that raised the alarm

UK-based monitoring group Nukewatch tracked the mission closely. The C-17 -- call sign RCH4574 -- first flew from Lewis–McChord Air Base in Washington state to Kirtland, which houses the world’s largest nuclear weapons storage site. From there, it continued on to RAF Lakenheath in Suffolk.

Nukewatch UK reported that the aircraft “almost certainly loaded up with a cargo of anything up to 20 newly manufactured B61-12 nuclear weapons.” Mid-flight, the pilot also informed ground control that the aircraft had “haz cargo” -- hazardous cargo -- onboard.

The plane landed in Lakenheath at 12:50 p.m. local time on July 17. During its stopover, the base imposed strict security measures, including halting all other flight operations and enforcing a 2.5-nautical-mile no-fly zone.

Two days later, on July 18, the aircraft flew back to the US, mission complete.

Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists, confirmed to Bloomberg: “There are strong indications that the US has returned nuclear weapons to the UK.”

Why the B61-12 Bomb matters

At the centre of this reported redeployment is the B61-12, a next-generation nuclear gravity bomb. Unlike older models, the B61-12 is fitted with a precision guidance tail kit, enhancing its accuracy.

The bomb has a variable yield ranging from 0.3 to 50 kilotonnes. For comparison, the Hiroshima bomb had a yield of 15 kilotonnes, making the B61-12’s maximum setting more than three times more powerful.

It can be deployed via US and NATO aircraft and is compatible with the F-35A -- the same jet Britain is currently acquiring. In June, the UK Ministry of Defence announced it would buy at least 12 F-35As, specifically citing their capability to carry B61-12 bombs.

A UK MoD white paper reinforced the alignment with NATO’s broader strategy, noting: “NATO’s nuclear deterrence also relies on US nuclear weapons deployed in Europe and supporting capabilities and infrastructure provided by Allies.”

The same paper also confirmed a significant shift in UK defence policy, stating: “This decision reintroduces a nuclear role for the RAF for the first time since the UK retired its sovereign air-launched nuclear weapons after the Cold War.”

Lakenheath’s new role

RAF Lakenheath is no stranger to nuclear weapons, having hosted them from 1954 to 2008. But over the past few years, the US has been quietly preparing for their return.

US Department of Defence budget records show major investments in nuclear “surety” projects at the base. One notable project is a 144-bed dormitory for airmen, justified by the expected “influx of airmen due to the arrival of the potential Surety mission and the bed down of the two F-35 squadrons.” Pentagon procurement records also reference a new “nuclear mission” at the site.

A message to Russia?

The timing of the transfer appears strategic. Just before the suspected deployment, US President Donald Trump warned of shortening the deadline for a ceasefire with Russia, saying he was “disappointed” in Vladimir Putin. Trump also greenlit Patriot missile deliveries to Ukraine through European partners.

Defence expert Sidharth Kaushal of the Royal United Services Institute told Bloomberg, “Capabilities such as the B61 can contribute to limiting the impact of Russia’s large advantage in theatre-level nonstrategic nuclear weapons.”

Both Washington and London have refused to comment, sticking to their long-held policy of not confirming or denying the presence of nuclear weapons.

Campaigners have demanded transparency. The Campaign for Nuclear Disarmament (CND) has called on UK Prime Minister Keir Starmer to clarify the situation in Parliament, citing national and regional security concerns.

Seven bases, six countries

With this shipment, analysts say B61-12 bombs are now deployed across seven NATO bases in six countries. While the bombs are on European soil, control over them remains with the United States: they can only be activated by direct order from the US president.

As NATO recalibrates its deterrence strategy, the return of US nuclear weapons to Britain is a powerful signal -- one aimed not just at allies, but at adversaries watching closely from Moscow to Tehran.