America does have a unique form of identity. Anybody in the world can become an American. Unfortunately, in more recent years, less emphasis has being placed on American culture and values as something immigrants should find desirable to adopt. It's starting to show.
This "inclusive" trait is shared with other nations. You can become British, or Canadian, no matter where you're from. Try becoming Japanese. Jury is still out on the French.
Oddly, all the inclusive societies I can think of are Western nations, but I haven't researched it. Are there exceptions?
Violent urges can be controlled by civilized nations, no matter how "natural" the source. Civilized people control dozens of "natural" impulses every day. As I said in my post, the miracle is that Americans aren't at each others' throats more than they are.
...it's instinctive. But the instinct can be fought. We're human beings, with the blood of a million savage years on our hands. But we can stop it. We can admit we're killers, but we're not going to kill today. That's all it takes. Knowing that we're not going to kill...today.
--James Tiberius Kirk