Park harbor, ergh, not quite.
But that was neither unprovoked nor unexpected. I'd suggest reading the classic "At Dawn We Slept" to get a bigger grasp of the situation and the attack. The abridged version is bigger than most trilogies and also available free at most libraries. Slow reading but something that should be read.
Among the many parallels, 9/11 was neither unprovoked (from their point of view) nor unexpected. Tom Clancy's best-seller and movie 15-20 years before the attack pretty much laid out how good a weapon an airliner could be.
And, as with the Japanese at Pearl Harbor, Al-Queda screwed up their attack and didn't gain anywhere near the victory that they could have had. (If the Japanese had had an accurate damage assessment after the first strike, they could have easily leveled all the refueling facilities in PH, which would have removed the primary source of US naval fuels for at least a year, giving the Japanese unchallenged control over the Pacific and time to build their empire.) Also oddly enough, one could say the long-term result of PH was a Japanese victory, boosting their role as a world power and leading economy. Al-Q hasn't quite gained that yet, but they've certainly put a permanent end to many American fundamental liberties, a huge victory for them.
But neither PH nor 9/11 was unexpected, there's plenty of documentation on both. Contested, debated, whatever, but the point remains, the events only surprised the folks who weren't paying attention.