Why did admiral leahy feel the use of the atomic bomb on japan was unnecessary?

Answer 1

He believed that continued bombing attacks and a naval blockade would

finish off all Japenese resistance. He also objected to the atomic bombs use on the grounds that other nations would develop the technology and

in some future conflict it would be used against the US. He also had moral

objections that our use of such a weapon made the US "common to the

barbarians of the Dark Ages".

Answer 2

Actually, he didn't. The notion that Leahy objected to the atomic bomb on ethical grounds is a distortion of a conversation he had with Truman after being notified of the decision to use the bomb (Leahy was unconvinced that it would work, believing that the Manhattan Project was a huge waste of funding up to the very last). In addition, Leahy did mention some objections on ethical grounds later in his memoirs (1950), but there is no evidence that he voiced such an opinion at the time of the decision to use them.

There is no evidence of any serious ethical objection to the decision to use the atomic bomb from anywhere in the U.S. command structure (either military or political). The only pre-use objections came from a very limited number of scientists involved in the Manhattan Project (and, only then, after the Trinity Test); objections on ethical grounds by politicians and military folks began only after the actual use of the weapons (and, the full effects were realized). There were political, military, and practical objections to the decision from a variety of the political/military command, but none of them severe, and none based on ethical grounds.

Much of the lack of objection is laid at the feet of incomprehension. The incredible power of the atomic bomb was simply unimaginable to those who did not have first-hand experience with it (either, directly through seeing a detonation, or via viewing of Photography/film of a detonation). Thus, the notion that the atomic bomb was something other than just a "bigger bomb" wasn't understood by anyone in charge. Expecting people to make some sort of ethical objection to something that they didn't really understand is unreasonable, and is the major factor behind the total lack of such ethical concerns.

Answer 3

Admiral Leahy is quoted as saying to President Truman (1945): "That is the biggest fool thing we have ever done. The [atomic] bomb will never go off, and I speak as an expert in explosives."