Had you have the wisdom and courage to fight those "non-existential wars" in due time, you perhaps wouldn't have to fight the WWII. As the recent history proves, fighting those non-existential wars all over the world served the humanity quite well so far in avoiding the next existential one. Putting a small fire out is much easier than fighting an inferno later.
Slobodan, that's not worthy of you!
You know perfectly well that hindsight can be as perfect or otherwise as desired. As we are, broadly, on the topic of 'nam, I guess that's one of the non-existentials to which you refer? So what was achieved, apart from the massive killings and arms marketing opportunities? The war was lost by the "good" guys - always a matter of definition and perspective - and in the end, the far-eastern world continued on very much as if nothing had happened, except that some still get maimed or totalled by mines nobody wants to feel responsible for or about.
As for putting small fires out, who's to determine what's a domestic fire and what's an external "police action", to use a term beloved of some states?
Looking at Muslim countries close to home, yet still safely far enough away (in a sense, but not when we invite revenge), interventions
or sidings with the internal/external affairs and personalities of such have resulted in a far worse fate for the poor inhabitants than had they been left under their own system of dictatorship. Does anyone other than the inevitable opportunist that harvests the fruits of unrest in the former lands of Saddam H. and Muammar G. feel any the better off since our kind intervention? Or, indeed, is the peasant of Afghanistan any the better off? Is
Europe any better off? Would it face the migrant crisis it faces today without those little fire-fighting expeditions?
And have the folks of the former USSR benefitted much from our proclaimed interest in their well-being? Or have vague dreams of joining a western prosperity made them suffer even more at the hands of the Bear? And that supposed prosperity; how much of it is myth, a life of perpetual debt to the card companies and/or the banks? Feels more like a state of ultra-high nervous tension, a constant living beyond one's means. And the crunch always comes: think 2008.
You know, all those pretty pictures you made of Chicago: not a lot of those buildings are owned by Joe Soap; most of them belong to faceless entities that are no more friendly to you or anyone else than the mugger in the street. Yet, it's visions of such richness that inspire folks outside the west to imagine that but for geography, they, too could have a piece of that. Yeah, just like I have a piece of Mayfair.