If the US military is weak it's because of the Executive and Legislative branches. When you send equipment overseas and don't replace the stuff at home you create a problem when your overseas deployments rotate back and need to train on non-existent equipment.

After a bit the troops get fed up and say, "F**k this sh*t! I ain't gonna re-up! Seen too much, put up with too much!"

It's not the military that's weak -- it's the civilian "leadership", which lacks imagination, a sense of the Constitution, and the guts to do more than to unquestionably support those who supplied them the money to be elected.