I’m of two minds regarding the testing.
I don’t doubt it’s necessity or strategic importance.
OTOH, exposing large swaths of the continental U.S. to radioactive fallout over decades seems a bit irresponsible in retrospect. Seems at some point in the 50s or early 60s, they should have realized how dangerous it was.
But judging the actions of those in the past by the standards of the present is rarely useful. The thousands of people, both civilian and military, who devoted their lives to the development, testing and refinement of this technology are pioneers and often unsung heroes.
No one can really say for certain how the world would be without the bomb, but it seems likely it would be far worse off if the U.S. wasn’t the first to develop and perfect it.
Near where the bombs were tested, the John Wayne movie “The Conqueror” was shot. Nearly everyone involved in that production developed some form of cancer later in life.
I think the lesson of history is quite clear; rival empires will eventually go to war with one another.
With out the fear of nuclear annihilation the USSR and the USA would have gone to war.
The existence of nuclear weapons and the means to deliver them rapidly and effectively prevented another even more bloody global war following WW II. The overwhelming presence of the BOMB made the USSR and USA limit their hostilities to proxy wars like Afghanistan.
However that era seems to be ending with bit players on the global stage like Iran being permitted to obtain nuclear weapons. Petty dictators like Iran's Imam having access to nuclear weapons could be the end of civilization.
People with no respect for human life having the power to end human lives by the millions is too scary to contemplate. And the fact that our national leadership having the ability to prevent it and standing idly by and doing nothing is incredibly frustrating.
US tests went underground in 1963. Granted some vented, but the release was nowhere near atmospheric tests.
Bikini Atoll is so radiated that people vacation and scuba dive there:
http://www.diveadventures.com/pages/destinations/Micronesia/bikini_lagoon.htm
People actually live in Hiroshima and Nagasaki. Look up the photos of the modern cities. All that radiation fear is overblown. Look up radiation hormesis when you get a chance.