Alo, "I think that USA really doesn't know the horror of war." Not nationally on its own soil in the modern era like Europe, Asia or other places. And that fact does have an impact on attitudes, I believe. Previously in the 20th Century it was always "over there." That's not quite the sense now, however, which has come as a bit of a shock. Although due to the variety of our population, immigration and ancestry, many people here now do know something of the horrors of war from a civilian point of view, either first hand from their own experience or from their parents or grandparents.
I recall one of the people I know most freaked out by Sept 11 was a young fellow from another country. He was in shock. He said, "We came here to live in peace, because America was safe. Now nowhere is safe." Many of our ancestors came and stayed in the US for the same reasons, not out of a desire to engage in world conquest, as some would assert. Even after Sept 11 there are people here who did not support the entry into Afghanistan and do not support this upcoming action.
Again, the population of the USA is not monolithic in composition or views or experiences. Something people in other countries sometimes like to forget when they speak of the evil Americans. Or perhaps they were referring to the Peruvians?
Good Luck on your examinations.