Because the U.S. told Japan to stop taking over China and Japan got mad. Also because Japan wanted to take over Hawaii. The attack was a surprise by the Japanese because they hoped to crush U.S. Naval forces in Pearl Harbor, including the carrier fleet. The carrier fleet was at sea, and the victory proved to only unite the U.S. and force America into war with Japan.
umm Japan
it was a surprise from japan that they were not expecting
It brought about the entry of the US into WW2, and the defeat and surrender of Japan.
Japan declared war on both the U. S. and Britain when they launched the surprise attack on Pearl Harbor.
Surprise gave the attackers a huge advantage over the defenders of Pearl Harbor.
Japan sought a true surprise attack and did not share this information for fear of it being compromised .
umm Japan
it was a surprise from japan that they were not expecting
Moving by stealth into attacking positions.
Just a carrier launched surprise attack.
F.D.R. declared war on Japan in retaliation to the Japanese attacking Pearl Harbor.
It brought about the entry of the US into WW2, and the defeat and surrender of Japan.
Pearl Harbor
This aspect is not mentionned in the movie, in which the attack is a surprise.
BECAUSE JAPAN DIDN'T DECLAIRE WAR ON THE UNITED STATES SO THEY WERE NOT PARPARED. AS A RESAULT OF JAPAN ATTACKING PEARL HARBOR THE UNITED STATES DECLEARED WAR ON JAPAN.
Japan did the attacking.
Japan declared war on both the U. S. and Britain when they launched the surprise attack on Pearl Harbor.