The attack on Pearl Harbor
In terms of a surprise military operation against an adversary the Japanese strike at Pearl Harbor was a resounding success when measured by the damage done to each side. In fact, in almost every military measure, Pearl Harbor was a failure. It disrupted the longstanding American strategy of sending the battle line to intervene in the event of Japanese attacks on the Philippines. Such a strategy would have likely failed anyway, the vulnerability of the older battleships to air attack being clearly established. What Pearl Harbor did was create national determination to destroy Japan, vilification of the Japanese as a race, and unification of the American people.
The Japanese also failed to bomb the oil supply tanks at Pearl Harbor, which if destroyed would have forced the United States Navy to abandon the anchorage and withdraw to the west coast. Abandoning Hawaii would have left Midway Island and its potential as a submarine base indefensible. The submarine base and repair yards at Pearl Harbor were relatively undamaged, and US submarines were very quickly conducting unrestricted operations against the ships of the Japanese Empire. Within weeks of the attack the United States was conducting nuisance raids against Japan, and by the end of June 1942, the Japanese were forced over to the defensive.