When you declare war, your intention is to defeat an enemy state -- even to the point of obliterating it.
The U.S. has no intention of ever "defeating an enemy state" these days. Now, we are a global empire whose primary purpose is to occupy these countries -- which means obliterating them defeats the whole purpose of going to war against them in the first place.
We do not occupy countries.
We do not loot countries.
We have no colonies.
If this is an “empire” we really suck at it and should open a history book and find out how it’s supposed to be done.