My dude, we struggle to take over poor middle-eastern countries. I'm not sure how you think us trying to take over the world would go.
It has however, at times, projected power for limited durations, with a goal to leave after. This has often been coupled with unclear goals, political maneuvering, and changing political situations back home.
This is very different from an empirical, king and country, nation wide focused goal.
These smaller actions have never mobilized the entire country on an expansionist, war time footing.
However, if we instead did something different called "try to take over a country"—which also does involve projecting power, and also occupying foreign nations for long periods of time, perhaps even up to and including 20 years—it would not be coupled with unclear goals, political maneuvering, and changing political situations back home.
> These smaller actions have never mobilized the entire country on an expansionist, war time footing.
So we've done these things which failed, but if we did a different thing, it would definitely succeed.
Instead, the literal goal was to give an entire generation of people time to grow up with democracy, set up institutions, have full bellies, excellent schooling, equality between the sexes, the list goes on.
The goal was never to stay, only to train, assist, help. The goal was to remove a threat, but at the same time make lives better. This is a laudable goal.
Regardless of the success or not, or even if the goal was doable, reasonable, the type of force applied, the way civilians were treated after, the negotiations with local politicians were all very different. To compare this sort of action, with whole scale war with the intention of permanent occupation isn't a fair comparison.
