You are American?
How about this then;
In using nuclear weapons on the Japanese, the allied forces were sending a message (Potsdam Proclamation - Surrender immediately, or face complete destruction). When Japan failed to heed the message, they were nuked again.
In firebombing large sections of Germany the allied forces were not only looking to break the morale of the German people, and also pressure the German government into an early surrender, but also sending a message to the advancing Soviet forces (look at what we are capable of).
According to some, legitimate targets. There were alternatives to both of these courses of action as the allied forces of course had standing armies of significant size and capability.
Therefore, can we then conclude that the 9/11 attacks were attacks on legitimate targets? After all, terrorism is a form of communication and groups such as Al Qaeda don't have the means to wage conventional warfare anyhow.