It is war, Krezy. "Terrorism" is a buzz word that has been given a strong, and justified, negative meaning. War is war. It doesn't change if you use buzz words. It doesn't change if you are in a uniform or not. It is war. In war you defeat your enemy or you will lose against your enemy. All is fair in war.
Attacking citizens on purpose would clearly violate the Geneva conventions.
Many soldiers had to die to get the Red Cross and the Geneva conventions established, and any belligerent power in war better remembers that. That includes the USA, too.