I understand that issue. But after many years study of WWI and WWII I am satisfied that America being dragged into the war only after several years of all-out battle by the actual principals is quite good enough. I like how those two wars worked out for us.
Fighting their battles FOR them is stupid, and suicidal in this age when surely the next general war will normalize nuclear weapons. All weapons are always normalized. Sometimes they are put aside by some adversaries, like poison gas and biowarfare, only to be used in brushfire wars or rebellions, as in Iraq and Syria and whenever any country gets desperate enough.
I don't know what you mean by "on our doorstep" if you aren't referring to ICBMs launching nukes at our whole East Coast from their home base: sounds like you are talking about Red Dawn, troops coming in thru Mexico, the only plausible "doorstep" we have (and quite a good one, militarily: illegals use it daily). I'm thinking only China is up to that kind of troop transport, but what do I know. And it couldn't be done while our Navy is intact: it would have to wait for Civil War dissolution here, I think.