This is a really interesting topic especially as it pertains to the concept of colonialism in a contemporary context.

I have a limited knowledge of the Bikini Atoll history aside from this encounter and it’s aftermath. The people living on the Bikini Atoll were more or less forced to move off of their ancestral lands. Most relocated to the very nearby islands: Rongerik Atoll and Kili.

The islanders were promised they could return to the island after the testing commenced. They moved peacefully. The testing was more extensive than was originally planned. There were several atmospheric detonations, an underwater detonation, and a detonation of a device 1,000 time stronger than Fat Man and Little Boy. The resulting fallout essentially made Bikini Atoll uninhabitable and the islanders were unable to return.

To further worsen the situation, Rongerik Atoll and Kili were unfit for civilization in the first place. Resources were too scarce to sustain the relocated islanders which led to medical and societal issues like starvation. As a result the nuclear testing at Bikini Toll not only deprived the islanders of their ancestral land, but also made them dependent on aid from the same authorities that took their lands.

Most significantly, the residents of the Marshall Islands were exposed to high levels of radiation from both the tests and their fallout. This as lead to sustained significant health problems among the islanders and their descendants. The radiation levels from fallout of Castle Bravo (the largest detonation on Bikini Atoll) reached the highest levels in recorded history. There have been some assertions that the island in now inhabitable, but studies have found radiation levels several times the recognized safe levels.

Recently the islanders and their descendants were awarded a ~$125 million settlement from the United States as compensation.

Bonus: the Bikini swimsuit was named after this nuclear test site. Here is an article on Bikini Atoll as it pertains to colonialism and queer theory. it’s a very good read. Edit: Bonus 2: Spongebob Squarepants is set in Bikini Bottom which is at the bottom of the crater produced by the nuclear detonations. I just read that studies have found an abundance of marine life in the actual crater and there is research going on to determine how these creatures are surviving in such irradiated conditions. (RadAway?) this research may help answer questions about cancer.

Edit: I realized I did not answer some of your questions. The people of Bikini Atoll were more or less tricked into leaving peacefully. They were told they could return soon after, which was a lie. They really didn’t have a choice. I could only imagine what it would have been like when a fleet rolled up on Bikini Atoll to “ask politely” if they will leave.

There were ~170 islanders on the island when asked to leave. A handful lived off of the island.

Was it for “the good of all mankind”? IMO, no. I would argue that nuclear technology is theoretically good when applied outside of warfare. This is a clear instance where the development and testing of nuclear technology is for the purpose of war. Which is to say, the testing could directly lead to the loss of millions of human lives. There is a caveat here, nuclear technology and a lot of other tech used in the private sector come from military development. But, It negatively impacted the lives of thousands of people and their descendants for generations to come. It poisoned part of our ocean and released a tremendous amount of radiation in our atmosphere. The tests made it a necessity for other countries to conduct their own which added to the damage on a global scale. I would also argue that nuclear detonations have turned public opinion against nuclear energy which is basically the good part about the technology so