Enzo:
I really don't think this is the forum to get too deeply into politics. Suffice to say I lived through the Vietnam era and don't remember any North Vietnamese or Viet Cong landing on our shores or bombing Pearl Harbor. Other examples include Panama and Manuel Noriega which never posed a threat. Neither did Granada. More recently, there was the infamous excuse of weapons of mass destruction.
The history of this nation is fraught with military actions for reasons other than self defense, starting at the beginning with Manifest Destiny as an excuse to steal land from the Native Americans and, later, Mexico. Over the almost 250 year history of the U.S., this country has sent troops literally dozens of times for reasons other than self-defense.
Bill, tgo