Respuesta :
The first nuclear weapon used against another nation was thrown to Japan at the end of World War II by United States. As part of a campaign to compel Japan to surrender, at the end of the Second World War, and in retaliation for Perl Harbor, two atomic bombs were dropped in Hiroshima and Nagasaki in 1945, it is also the first use of atomic attack against another nation.
The answer is: by United Sates during the World War II.