The US would have eventually prevailed with the loss of the carriers, the fact that they were not destroyed just shortened the eventual reversal.
The Japanese underestimated how angry the American citizens would become over such an attack. A declaration of war was supposed to be delivered about an hour before the attack, but decoding took longer than anticipated and no declaration was in place at the time of the attack.
Yamamoto hoped to engage the United States at the negotiating table and warned of a protracted war. He had also campaigned for more Naval Air instead of the huge Battleships Musashi and Yamato, which pretty much remained idle during much of the war due to fuel issues.
The Coral Sea battle stopped the (I believe) Port Moresby invasion force and affirmed that the Carrier was the new boss, the Battle ship was going to play second-fiddle now His Midway campaign also violated many Mahanian principles, of which the Japanese Navy was a big believer in.
Their Aviator training program simply could not keep up with attrition, Midway really hurt them there.
The third wave of attacks at Pearl that would have taken out the fuel reserves and drydocks were also another mistake. The fuel at Pearl on the 7th was used in June at Midway.
Admiral Yamamoto predicted what would happen.
