The entire reason why the US entered the war was because of the attack.
No, that was a convenient excuse. Roosevelt must’ve thought Christmas had come early when he got the news.
Do you think if they did, they would’ve used them immediately to force a quick surrender instead of dragging out the war for years causing millions of deaths?
No, because B-29s didn’t exist yet either, and they couldn’t take off from aircraft carriers in any case. The US would’ve had to conquer its way across the Pacific to get within bomber range either way.
Roosevelt wanted to get involved but had no way to get the public to go along with it. The Japanese helped him out.
And how exactly do you imagine the US could’ve used such weapons against Japan without transporting them to Japan?