After all, Japanese officials obviously knew that bombing Pearl Harbor would mean war with the United States, a country that had been instrumental in winning World War I.

The U.S. was also a country whose industrial capacity was unmatched anywhere in the world. Japan knew that American industrial centers could be converted into the production of war materiel. Japan knew that there was no reasonable possibility of bombing those industrial centers.

And it wasn't like the attack on Pearl Harbor was the first stage in a Japanese military invasion of the United States. Immediately after wreaking the destruction at Pearl Harbor, the Japanese bombers and their fighter escorts returned to their aircraft carriers.  There was never even the remotest possibility that Japan was going to invade the western coast of the United States. They knew that they didn't have the military capability to pull off such an enormous endeavor.

Moreover, let's not forget that Japan was embroiled in a foreign war in China. Why attack the United States, which would then require Japanese forces to fight on two fronts — one in China and one against the United States?

Why then did Japan do it? Why attack the United States, knowing that the attack would mean war with the most powerful nation in the world? On the surface, the attack makes no sense whatsoever.