Nuclear testing at Bikini Atoll consisted of the detonation of 23 (or 24) nuclear weapons by the United States between 1946 and 1958 on Bikini Atoll in the Marshall Islands. Tests occurred at 7 test sites on the reef itself, on the sea, in the air, and underwater. The test weapons produced a combined yield of about 77–78.6 Mt of TNT in explosive power. After the inhabitants agreed to a temporary evacuation, to allow nuclear testing on Bikini, which they were told was of great importance to humankind, two nuclear weapons were detonated in 1946. About ten years later, additional tests with thermonuclear weapons in the late 1950s were also conducted. The first thermonuclear explosion was much more powerful than expected, and created a number of issues, but did demonstrate the dangers of such devices.
From Library of Congress.
Maybe because they are more interested to test on land, where most of the strategic targets are, but as far away from civilization as possible and on their territory, so it ends up on an island.
Gee, if only the US had possession of a bunch of uninhabited islands…
Of the cruel things to do, I'm at least glad they found a place with only 167 people and destroyed their home.
Though, they still could have used the desert, even if they were a bit afraid of just how large the yield would be.
Iirc they ended up being a little too interested in the health impact on the inhabitants for it to be considered unintentional or collateral. The way i see it, they just wanted to test on humans but didnt want to deal with human rights advocates so they picked some random little island.