No argument that the US spent a lot. Trouble is I can't see where anybody gained. US families certainly took a beating. 

Afghanistan was a US response to Muslim-Arab retaliation - 9-11. Just another battle between the US and Arabs which had been going on since the US financed the takeover of land in Palestine

 WW1 and WW2 were European wars that we should not have been involved in. The US got involved in WW2 in the same way it got 9-11, namely the US interfered in a war between China and Japan on behalf of China. Japan retaliated..  

Korea was ostensibly to stop the spread of Communism. Communism was a loser as anyone familiar with gov`t run anything knows. Just a matter of time.