Public domain
The UK detonating a nuclear weapon in the Monte Bello Islands
Britain joined the nuclear club as its third member, after the US and Soviet Union, detonating a nuclear weapon in the Monte Bello Islands - now a marine conservation area - of Western Australia in October 1952. Britain and Canada had been part of the Manhattan Project developing the world’s first nuclear weapon during World War Two but were excluded from access to information by the US Atomic Energy Act of 1946. The UK went ahead with its own programme and conducted 21 tests at various locations, before another 24 jointly with the US. The UK is one of five nuclear weapon states under the Treaty on the Non-Proliferation of nuclear weapons (NPT).
