The US government documents, declassified by the National Archives and Records Administration after about 70 years, show London was involved in Washington’s decision to carry out the nuclear attacks as a close ally.
London’s support was officially expressed to the US officials one month before the first and only nuclear attacks on a real target killed an estimated 250,000 civilians on August 6 and 9, 1945.
The go-ahead was given in a meeting of the Combined Policy Committee of the US and the UK in Washington on July 4, 1945 in which British officials referred to the nukes as Tube Alloys, a codename they used for their research on nukes and plutonium at the time.
British Field Marshal Sir Henry Wilson told the meeting chaired by U.S. Secretary of War Henry Stimson that the British government “concurred in the use of the T.A. weapon against Japan”, Kyodo News Agency reported.
“The Governments of the United Kingdom and the United States had agreed that T.A. weapons should be used by the United States against Japan, the agreement of the British Government having been communicated” by Wilson, the documents said.
According to the documents, the initial agreement for the use of nukes against Japan when they are developed was made back in September 1944 in a meeting of the then US President Franklin Roosevelt and the then British Prime Minister Winston Churchill.