I had not about it in those terms, but, I think you are right, had he been there or here, there were going to be folks either murdered or injured, it just happened to be in the first days of the war.
As I see it the man was destined to kill Americans. He says he attacked due to being sent to kill his muslim brothers but I think he would have eventually decided that he was killing them by proxy simply be being an American citizen.
It's purely my opinion but I think this guy would have eventually launched an attack right here in America and likely killed American civilians.