I'm not convinced there's been a war since the Revolutionary War that we've needed to fight.
Well, nobody ever really needs to fight a war, do they? It all comes down to whether one considers one's way of life to be valuable enough to fight for, or whether one considers allies to be expendable.
America is defended primarily not by any super-weapon, missile or plane. It is defended by several thousand miles of water, making the invasion of America extremely unlikely until foreign powers are able to 'beam' armies to their desired combat zone a la Star Trek. As such, one has to ask where one draws the line. Is it, for example, planes flying into the WTC? Or planes bombing Pearl Harbor? Nether event in isolation is going to result in the USA being overrun.
As I said, nobody needs to fight a war. It is always possible to capitulate instantly to the demands of anyone who is more militaristically minded. Like the Brits were 200 years ago.
I'm not convinced our way of life has been threatened since the Revolutionary War.
I won't try to convince you, but I certainly disagree.