Tell that to all the legitimate states in the world, because everyone of them including the US bombs a city before putting boots on the ground. Were you paying attention during the Gulf wars?
How many civilians were killed in the Gulf War?
Most of the fatalities were American, while 47 British personnel died. According to the Imperial War Museum, between 20,000 and 35,000 Iraqi soldiers died during the ground war. Civilian deaths resulting from the conflict are estimated at between 100,000 and 200,000.