Here is the question. Why should America pay it? Like the way I see it why should America care if Russia invades Ukraine, or China Taiwan? Nations get attacked by others all the time, does anyone care about Saudi Arabia attacking Yemen? The Israelis if they do something bad to Palestinians? America should not try to make a world empire for the elites and globo homo. We should be concerned with the New world. As long as old world nations don't try to set up in the America's we should leave them be.
Because 1) it's 2022, not 1822, and 2) there are a wide variety of options between "Making the World Safe For Democracy" and "Going Full Sankoku Japan."
In the case of Russia/Ukraine and China/Taiwan, it's because their actions actually impact us and our neighbors. And the fact that where distances used to require months to travel now can be covered in hours. And the fact that we have significant interests in Europe, Asia, and the Middle East, for different reasons.
The "globalism" view has pretty much gone out of fashion, but working closely with friendly nations means that we don't have to be The Guy in every situation (although our sheer size and the resources we can bring to bear as a result mean that if we have to, we absolutely can).
With Russia and Ukraine? We really don't want to have to remilitarize Europe like we did post-1945, and worry about what's currently going on being repeated over and over in other countries. And part of the reason is that we've been shipping equipment and other support to Ukraine so we *don't* have to take a more active role.
With China and Taiwan, it's because the latter is actually a democracy and a friendly country, whole the former is our biggest geopolitical rival and even if we tried to ignore them, they are going to focus on us, simply because we are too big to be ignored. Likewise we really don't want the Korean War going hot again, nor do we want China deciding to start wars on its borders again and causing who knows how many humanitarian crises as well as massive disruptions in the economy. Like it or not, it impacts the U.S. directly.
Burying our heads in the sand does not and has never worked. We have tried that, repeatedly, and it failed.
Oh, and a final note on the Monroe Doctrine: The only reason it stuck was because there was a global power willing to help us enforce it (the British). The U.S. never had the ability during that time to project power beyond Mexico and the Caribbean...and even by 1914 it was clear we couldn't do *that* much in response to what went on even south of the border.
