On January 31, 1950, President Harry Truman announced his support for the development of the hydrogen bomb, a weapon intended to be many times more powerful than an atomic bomb. Only two years later, the U. S. successfully detonated “Mike,” the world’s first hydrogen bomb, in the Pacific Marshall Islands. The 10.4-megaton thermonuclear device vaporized an entire island and left behind a crater a mile wide. Three years later, the Soviets also had a hydrogen bomb.
