that's why a naval blockade is a terrorist act of war, and why Japan was justified in attacking Pearl Harbor
A naval blockade is indeed an act of war. I guess you threw the word "terrorist" in there because - you like to abuse what words mean?
But the U.S. had imposed no naval blockade on Japan before the Pearl Harbor attack. The U.S. had halted U.S. trade with Japan in oil and scrap metal (but nothing else), but this is not what the word "blockade" means. A blockade is using armed force to prevent shipping (or other forms of transport) from third parties from getting entering the blockaded nation. Nothing like that was happening. The U.S. had also closed the Panama Canal to Japanese shipping, but again, not a blockade. Japan was free to go 'round the Horn and on to Japan without interference.