Answer:
America and Japan were not at war with each other
Step-by-step explanation:
The Japanese attack on Pearl Harbor came as a surprise because America was expecting an attack from Japan but not on Pearl Harbor since America had put an embargo on supplies on oil, steel and scrap iron. As a result of the embargo, Japan became desperate and moved into territories occupied or controlled by America and Western powers such as the Indochina, India, Singapore, The Dutch East Indies and the American controlled Philippines. This was a risky move made by Japan but they had to take a chance due to the embargo America put on them.
America was into negotiations with Japan to end Japanese expansion, however the negotiations were not yielding positive results as expected by America so the negotiations were suspended and America suspected an eminent from Japan but did not expect it to be on Pearl Harbor.