Perhaps the US economy (and politics) is resilient enough to handle it and not crash outright, but poorer folks in the US feel the squeeze of inflation and lowered wages due to cantillion effects.
US debt in 2000: $5.6T, in 2022: $30.9T [1]
The larger wars of this century drove about a quarter of debt growth. Major but not the majority. That more people will risk life and limb to immigrate than emigrate indicates to me that as bad as inflation is, living elsewhere is still worse.
0. https://time.com/3651697/afghanistan-war-cost/
1. https://www.statista.com/statistics/187867/public-debt-of-th...
Sure the US may still have a higher quality of life than many others, it doesn't mean that Americans lives couldn't have been better. Also I believe the US recently actually had decreases in both life expectancy and younger generations prospering fincially. So we didn't collapse, but we're not healthy either.
Could things be better in the US if it did not spend the way it does? That is a difficult counterfactual. The well adapted US political system never voluntarily decreases taxes, so a safe assumption is that spending/deficit/debt would be the same.
A significant amount of war funding was spent on the MIC, which employs upper middle income US persons in engineering, logistics, HR. The rest is spent on consumables (also from the US) and bribery, which eventually finds safe harbor by holding large bricks of US $100 bills on the low end or US luxury dwellings on the high end.
In the counterfactual, what would have happened to all those white collar suburbs and Miami penthouses?
We'll give them three quarters of a trillion dollars every year no matter what they spend it on so in reality it doesn't matter if they're war fighting or not, they own us, well 50% of our discretionary tax dollars anyway.
UBL may not have achieved his primary goal but he got many concessions: Americans lost many freedoms, trust in government is significantly lower compared to pre 9/11 and given what happened on Jan 6 and everything that led up to it, we may look back at 9/11 as the point which set the stage for the eventual breakup of the union.
I donno about this. Adversaries might just as well conclude the opposite, that the US can blow that kind of cash on SLS and other dumb stuff all over the world without major problems. IIRC, UBL's thesis was A-stan is/was the graveyard of empires and would also be the US', but it turned out to be an otherwise forgotten Pentagon rounding error.