Becuase I hate you!
No they did not yet
The U.S. used the pacific atolls because they were isolated from large population centers and because the Marshal Islands (where many of these atolls were) were entirely under U.S. control after WW2, so could freely involuntarily evacuate indigenous populations of the atolls that testing was planned on. The USSR did all of their testing inland for security reasons (they also did not have control over any atolls). The British did much of their testing inland on Australia and some in the pacific on Christmas island. The French did their testing in the Sahara desert. The Chinese did all of their testing inland for security reasons. etc.
Atolls
There are high mountains, coral atolls, and it is located in Oceania.
Kiritimati or Christmas Island
atolls
Volcanic islands, coral atolls
Tokelau consists of three coral atolls, Atafu, Nukunonu, and Fakaofo.
Also called atolls they usuallyb have coral reefs and tropical trees.
coral reefs barrier reefs fringing reedfs atolls
An atoll is a ring-shaped coral reef that forms around a lagoon. Charles Darwin's theory of how atolls are formed as remnants of ocean volcanoes is generally considered fact.
A circular coral island that encloses a lagoon is called an atoll. Atolls are typically formed from coral reefs that grow around the rim of a submerged volcanic island.