The United Kingdom is one of the five official nuclear-weapon states under the Treaty on the Non-Proliferation of Nuclear Weapons. It formerly possessed biological, and chemical weapons.
A Trident missile launched from a submerged ballistic missile submarine.
Little Boy bomb
The United Kingdom became the third country to develop and, in 1952, test nuclear weapons. The UK is one of nine nuclear-armed states, and one of five recognized by the Treaty on the Non-Proliferation
United Kingdom and weapons of mass destruction
…states under the Treaty on the Non-Proliferation of Nuclear Weapons. It formerly possessed biological, and chemical weapons. As of 2025, the UK possesses a stockpile of approximately 225 warheads, with 120 deployed on its only delivery system, the Trident programme's submarine-launched ballistic missiles. Additionally…
HMS Victorious, one of four nuclear-armed ballistic missile submarines of the Trident programme
James Chadwick (left), the head of the British Mission, confers with Major General Leslie R. Groves, Jr. (right), the director of the Manhattan Project
President Harry Truman and the prime ministers Clement Attlee and Mackenzie King boarding USS Sequoia for discussions about nuclear weapons, November 1945
William Penney, Chief Superintendent Armament Research, was in charge of atomic bomb development.