Is London shifting from nuclear deterrence to war-fighting?

Bulletin of the Atomic Scientists

The United Kingdom initiated a major shift toward tactical nuclear war-fighting in June 2025 by acquiring 12 nuclear-capable F-35A stealth fighter jets to join NATO's air-launched nuclear mission. This decision, coupled with the suspected deployment of United States B61-12 gravity bombs to RAF Lakenheath, introduces high-precision, variable-yield counter-force capabilities to Europe.

These developments build upon London's quiet 2021 policy reversal that raised its maximum nuclear warhead cap by over 40 percent to 260. By altering its doctrine to introduce a "right to review" nuclear use against non-nuclear states, the nation has effectively abandoned its traditional minimum deterrence posture. Integrating dual-capable aircraft raises severe risks of accidental escalation, as adversaries cannot distinguish between conventional and nuclear F-35A sorties during a crisis. Consequently, this expansion of non-strategic capabilities undermines European strategic stability and stokes a destabilising arms race with a conventionally inferior but nuclear-armed Russia.

Comment

Western nuclear integration lowers the threshold for tactical deployment in regional conflicts. This shift forces adversaries to adopt highly responsive launch-on-warning postures. Such hair-trigger readiness increases the probability of catastrophic miscalculation during conventional skirmishes. The normalisation of sub-strategic nuclear options severely degrades global deterrence stability.