My God, Japan has invaded Manchuria, as well as China!
Why we're going to bleed them dry with an oil and a steel embargo. Without these goods that run their Navy, Japan will be forced to cease her conquest.
What're we going to do?
Pearl Harbor, Hawaii, and the Surprise Attack
Japan's doctrine of imperialism, similar to England's, dictates that a nation must have sufficient land to draw resources from, and trade with, in order to be wealthy, and successful. This led to Japan's brutal conquests over China, Manchuria, English controlled India, and numerous other countries, and island groups.
American Carriers at Sea
Due to Japan's conquests of China, Manchuria, and various other small factions, the U.S. sanctioned embargoes on the trade of American steel and Oil to Japan. Since America supplied more than 70% of Japan's oil that they used to fuel their Navy, Japan was forced to take drastic measures to ensure the survival of their ever-expanding empire.
F.D.R. "Date Which Will Live in Infamy"
"Yesterday, December 7, 1941, a date which will live in infamy..."
Their hand influenced by American foreign policy, and Japanese hierarchy, Japan attacked the U.S. naval base at Pearl Harbor, Hawaii, on December 7, 1941. The attack resulted in over 2,400 American lives lost, 3 battleships left beyond repair, and America's entrance into the war.
U.S. Rebuilds her Navy
During the dastardly attack on the U.S. Naval base at Pearl Harbor, the Japanese's main targets were out at sea - the American carriers. This stroke of luck is what denied the Japanese their full victory at Pearl Harbor, and what would lead to battles like the Coral Sea, and Midway. If the American carriers had been destroyed that day at Pearl, there is no telling how the tides of war would have changed.
On December 8, 1941, President Franklin Delano Roosevelt made a short speech, saying, "No matter how long it may take us to overcome this premeditated invasion, the American people, in their righteous might, will win through to absolute victory."
After Pearl Harbor, America started to rebuild, and modernize her Navy, eventually making it, controversially, the best in the world. It would ultimately be this Navy, with support from the United States Marines, which would bring the Japanese aggressors to their knees.