Also since WW2, none of these countries posed a real danger to the US Public, plus people in the US are not invested. Compare what the public in the US had to do in WW2 compared to these "wars".
If the life style of the Average US person is affected like in WW2, then you can bet these "wars" would never happen. Just look at what a slight raise in US Gas Prices cause. If gas prices did not go up, people in the US would not care at all what Trump is doing to Iran.