The United Kingdom government has unveiled its largest defence investment plan since the Cold War, committing £15 billion over the next four years to modernise and expand its military capabilities. Prime Minister Keir Starmer announced the package on Tuesday, framing it as a necessary response to a rapidly shifting global security landscape. The plan pushes UK defence spending to 2.7% of GDP, with a stated trajectory toward 3% and a longer-term commitment to reach 4.2% by 2035.

The announcement caps nearly a year of internal debate and follows a Strategic Defence Review published earlier in 2025, which explicitly frames preparation for a potential confrontation with Russia as a central priority. The urgency behind the plan has been building since Russia's annexation of Crimea in 2014, and intensified after the full-scale invasion of Ukraine in 2022 and the return of Donald Trump to the US presidency, which has prompted Washington to push European allies to shoulder more of their own defence burden. Last week, the UK also announced the purchase of 12 F-35A fighter jets capable of carrying tactical nuclear weapons, which the United States has reinstated on British soil.

A central focus of the investment is what military planners are calling the