The Day of Infamy. I suppose you could argue that 9-11 has suceeded December 7, 1941 in our national consciousness as the "Day of Infamy"
though the consequences of 9-11 have been much less dramatic and traumatic (except for those on the front lines in the War on Terror). Of both these
"dastardly" acts the words attributed to various Frenchment on the execution of the duc d'Enghien apply:
"It was worse than a crime, it was a blunder!"