That's not what I've noticed with Japanese people, FWIW. There is a very nationalistic streak of pride, that (for the rightwingers, at least) can be easily deformed into the denial of the historical record that is distressingly common, to this day.
It's probably due to us all being affected by our environment -- being an island society makes it easy to be isolationist and form a "they're out to get us" worldview.

I saw this strange sense of denial around the documentary "The Cove", as well, FWIW, although that's a different situation.