[Lonesome in Massachussets]

The Japanese suffered from poor tactics, poor strategy and an industrial base inadequate to their ambitions.

However, they believed that America lacked the stomach for a long, bloody war. Their expectation was that America would not fight a long bloody war to liberate China and the Philippines and would come to terms with them in 1942. They did not reckon with Americans' outrage at their perfidy.

[buck61]

Admiral Isoroku Yamamoto, who planned the Pearl Harbor attack, predicted in 1941,

We have awakened a sleeping giant !!!

[FreeAtlanta]

There mistake was that they fought an American population that had not degenerated to what we have today.

[Tallguy]

However, they believed that America lacked the stomach for a long, bloody war. Their expectation was that America would not fight a long bloody war to liberate China and the Philippines and would come to terms with them in 1942. They did not reckon with Americans' outrage at their perfidy.

Had the Japanese studied the 250-year American campaign against Native Americans they'd have learned that the US Government could be pretty patient and ignore major reversals like Pearl, Corregidor & Wake Island.