Britain Deploys 3 Nuclear Submarines Amid Tensions with Russia

The British newspaper The Times revealed that three of the four submarines comprising the UK’s nuclear deterrent fleet are at sea, with at least one armed with ballistic missiles carrying nuclear warheads, in a move described by naval sources as “unusual.”

The fourth Vanguard-class submarine, HMS Vanguard, is currently undergoing extensive maintenance at the Devonport naval base.

The Times quoted a source in the British Royal Navy who described the simultaneous presence of three nuclear submarines at sea as “unusual,” without offering an explanation for this deployment.

A former senior naval official also expressed surprise at the presence of the three submarines at sea, viewing it as a positive sign of improved conditions. He stated that this development could help reduce patrol durations and improve working conditions for submarine crews.

However, he ruled out the possibility that the move was linked to sending strategic messages, in reference to escalating tensions with Russia. According to the newspaper, the last known deployment of three submarines from this fleet at sea occurred more than five years ago.

This development follows recent operational readiness challenges faced by the UK’s nuclear fleet. In recent years, the number of submarines capable of active duty dropped to two, as the other two underwent repairs and maintenance.

Consequently, patrol durations were extended. One recent patrol lasted 205 days away from base, while each of the last nine patrols lasted more than five months, according to the newspaper, citing the specialized maritime website Navy Lookup.

The newspaper quoted Tom Sharpe, who served 25 years in the Royal Navy and commanded four warships, stating that improved operational readiness for submarines would be a positive development. He added that having two submarines at sea is not unusual; typically, one is on a continuous nuclear deterrent patrol while the other undergoes sea trials.

Sharpe explained that submarines usually undergo sea trials to verify their readiness before being armed with Trident missiles.

The Vanguard-class submarines were originally designed for a service life of 25 years but will approach 40 years of age by the time they are replaced by Dreadnought-class submarines, expected to enter service in the early next decade.

The UK submarine fleet comprises nine submarines in total, including five nuclear-powered Astute-class attack submarines. However, a report by Robert Clarke, defense analyst at 878 Research, indicated that none of the Astute-class submarines would be available for operation throughout the summer of 2026.

Unlike the Astute-class submarines, which are designed to track and engage targets using Tomahawk cruise missiles and Spearfish torpedoes, the primary mission of the Vanguard-class submarines is to remain undetected and maintain positions that allow them to execute a retaliatory nuclear strike if necessary.

These submarines can remain submerged for months, following carefully planned routes to avoid detection by enemy submarines and ships.

This naval deployment coincides with growing European interest in nuclear capabilities amid tensions with Russia and increasing concerns about the future of US security commitments to Washington’s European allies.

Paris stated that the training included French air-delivered nuclear capabilities, a step reflecting growing defense cooperation between the two countries. The two sides agreed in July 2025 to enhance cooperation in the field of nuclear arsenals, in response to escalating threats facing Europe and uncertainty regarding the US ally.

British Army Chief of the General Staff, General Roland Walker, warned that current international conditions entail severe risks and that the country may need its armed forces to engage in war.

Walker stated in earlier remarks last October that readiness for combat has returned to the core of British national thinking, and that the era in which the country was not required to contemplate armed conflicts has ended.

The newspaper notes that Britain’s sea-based nuclear deterrence relies on Trident II D5 missiles launched from Vanguard submarines; this provides the capability to carry out a nuclear strike but offers fewer options compared to Russia.

The newspaper describes Britain’s nuclear doctrine as akin to an “on or off” choice, reflecting its reliance on strategic ballistic missiles, whereas Russia possesses a broader range of nuclear options, including tactical weapons with relatively lower destructive power.

Britain plans to purchase 12 F-35A aircraft, expected to arrive by the end of the current decade. These jets are capable of carrying US B61 nuclear bombs, which can be configured with reduced destructive capabilities, enabling their use in tactical nuclear weapon scenarios.

A spokesperson for the Ministry of Defence emphasized that nuclear deterrence remains the cornerstone of the country’s national security, providing round-the-clock protection for Britain and its NATO allies.

He added that Britain remains the only European ally committed to using its nuclear deterrent to protect the Alliance, noting that all NATO members already benefit from this nuclear umbrella.