OK, Jack Ma, what if USA wasn't strong enough to be feared by others? What would we have? War. Pax Americana is probably a great investment, others might want to be thankful (up to a point) as peace has lifted all boats. Plus, that $14 Trillion was invested in US companies, granted military leaning ones but still the money was put back in our economy. And USA sold and will sell a lot of weapons because of that R & D
Do you call the situation in the Middle Ease peace? Not saying that it's the US's fault ...
Plus it started recently and war is (kinda) the default state in some places. It can be a lot worse