The Bomb and The Atoll
 

Four months after the end of World War II on 10 January 1946, US President Harry S. Truman approved the execution of Operation Crossroads.  A military operation with the task of detonating 3 Atom Bombs to determine the bombs affectivity against a naval fleet.  Soon after its approval, Bikini Atoll was selected as the test site. 

The US Military saw Bikini Atoll as the perfect site.  It was in an area controlled by the US, it had predictable wind patterns, it had a small population (it could easily be relocated) and most importantly; it was absolutely in the middle of nowhere.

On July 1st 1946 the worlds fourth Atom Bomb was detonated on Bikini (Trinity, Hiroshima and Nagasaki were the first 3).  Post war nuclear testing had begun and Bikini Atoll was at the forefront.

With the beginning of the Cold War and the imminent nuclear arms race with the Soviet Union, the United Sates continued and expanded its nuclear testing programs.  Other nuclear test sites were selected, but Bikini remained on the list. 

Following Operation Crossroads, the US military used Bikini for an additional 21 nuclear tests.  Among them, the most powerful nuclear bomb ever detonated by the US: Hydrogen Bomb code name Bravo.  With a yield of 15 megatons, it was 750 times more powerful than the fission bomb dropped on Hiroshima, Japan.

Bravo's Mushroom Cloud
 

Atmospheric nuclear testing finally ended with the signing of the Atmospheric Test Ban Treaty by the United States and the Soviet Union on August 5, 1963.  By then the US had detonated 317 nuclear bombs and the Soviet Union had detonated 221.  In a span of 18 years the world had experienced a total of 538 nuclear explosions.