It's the historical significance, I believe. It was the first time in our history the mainland of the USA was attacked, so successfully.
Pearl Harbor was as bad as 9/11, War of 1812 was worse, the USA was invaded by Britain and managed to burn down the White House.
Obviously, Teejay, I was talking about twentieth century history, when I mentioned "mainland attacks" and deliberately omitted the attack on our most vulnerable occupations. Midway and the Philippines was a rugged battle as well. Pearl Harbor was not part of our union when it was attacked by the Japanese. We still fended that one off and recovered fairly well, I think. They haven't been interested in renewing hostility, since.
Of course in the early time of our union, the Brits did not want to give up their cash cow and we had to prove more than once that we were serious about our independence from their monarchs. Relations were stressed for decades, but again Britain gave up their attempts and even began to emulate some of our leaders' ideals. That war was won, too.
I fear that we will become our attackers in this case, because of how knee-jerk-ish we have proven to be. The 9-11 attack created an atmosphere where the average Americans gladly gave up many of their freedoms for security of a martial state, instead of fighting back as individuals. That is the historical significance I was referring to. Sorry to create a mixed context. It is very scary.
