The US has 40% of the world's weapons expenditure, and about 40% of the world's wars, measured by value of weapons used in wars (my guess). The US is cut off from the rest of the world by two oceans, and trees on the North and desert on the South, and absolutely nobody wants to conquer it. So the wars we are in are usually on the other side of the world.
Exception 1? In 1812, the British attacked, and in Washington DC set the executive mansion on fire, subsequently repaired and referred to as 'the White House'. There was no adequate military defense so the US personnel withdrew into the swamp and returned a few days later after the British troops had gone. The means of defense were in this case, space and time.
Exception 2 In 1941 the attack on Pearl Harbor. Mitigating factors are that Hawaii was not at that time a US state, and the US had imposed an oil embargo on Japan, so attacking the navy was an obvious thing to do, and it wasn't that much of a surprise as war with Japan had been regarded as inevitable for over a year, and Japan was down to 2 weeks of oil left, so we did know the timing, and we could have avoided war by not embargoing Japan and not leaving ships so far from the US, so technically it was a war of choice, maybe, but not much of a choice. Having fascist countries across both the Atlantic and Pacific Oceans, just on the other sides in both cases, was not considered a tolerable situation. Nor was the expansion of Japan into Manchuria and Indonesia. It is this attack that almost a century of US policy of keeping a huge military is based on. I would propose that having the World's largest expenditure on weapons, or being in team that did might in some cases be justified, but 40% and just on our own, and in NATO as well, and with lots of nukes, is overkill.
