Foreign policy and its failure

Why has our foreign policy failed?
I have come to believe that it is because we meddle endlessly and needlessly. We give aid to other nations, never mind that the money could at LEAST be spent improving the US instead. We have troops in over 100 nations, many of which have been existing deployments since WWII. Who actually threatens this country?
No one.
Why do terrorists attack us?
Because we are there. We assume people in other nations cannot solve there own problems. This is garbage. France did not occupy the US after helping us win the Revolution. We give up sovereignty to NATO and the UN, let them deploy OUR troops, and command them. This is not in our interest, but the interest of weapons makers, of international contractors. The interest of the US would be to LEAVE THEM BE. If they want to trade with us, great. We have no right to dictate the direction of other nations.