Japan's history and why they entered the war

As we know, the bombing of Pearl Harbor is what finally dragged America into WWII. But the events leading up to this attack go almost a hundred years back. 

Until 1852, Japan was an isolationist country; they refused to trade with anyone other than the Dutch, and even then only in one city. But that changed when America barged in and said "you're going to trade with us, or we'll destroy your cities." It made Japan realize that by isolating themselves, they were behind on every technology and not ready to be powerful. To rebuild their country, they based themselves as much as possible off of Western society, with a parliament and such. To keep in line, they wanted to engage in imperialism and take some colonies, to make themselves look strong. Their target was the South Peninsula of Korea. The complication there is that it was under China; it sent them money every year. The Japanese forced some treaties onto Korea, but it wasn't under their control. China sent troops to Korea to squash a rebellion, and that broke treaties made earlier. The Japanese also sent in troops, and fighting between Japan and China broke out (First Sino-Japanese War from 1894-1895).China lost it badly. Japan went around being an imperialistic power until the interwar period, when countries started getting tired of imperialism. China had started to reform itself by then, and Japan was scared of losing China. They invaded Manchuria and renamed in Manchuko, but nobody would recognize it as a state. Japan and China ended up fighting another war (Second Sino-Japanese War from 1937-1945), which stretched Japan to it's limit. 

The U.S. started putting embargoes on Japan, because of an attack on a U.S. ship and the atrocities commuted by the Japanese in the Second Sino-Japanese War. They figured that if Japan was limited in their access to war supplies, they would have to pull out of the war eventually. Instead of that, Japan became more set on fighting the war, and winning it. They were desperate for resources, and turned to the South Pacific. Unfortunately for them, the South Pacific was colonized by the American and British. They launched attacks on the South Pacific and Pearl Harbor at the same time, to destroy fleets and gain rubber/oil. 

Pearl Harbor was not a target that America expected Japan to go for. It was 4,000 miles away, and American informants were sure the attacks would go to the Dutch East Indies, Singapore or Indochina. Because of this, Pearl Harbor was pretty much undefended. Almost the entire navy fleet was there, and hundreds of airplanes as well. To the Japanese, it was an amazing target. Their plan was to destroy the fleet, and they almost did. They sunk two ships, and injured 18 more. 300 airplanes were destroyed, 2,403 sailors, soldiers and civilians were killed, and about 1,000 people were wounded. However, the carrier was the new thing in ocean warfare, and none were at Pearl Harbor when the attack happened. The Japanese also left up the oil storage depots, repair shops, shipyards and submarine docks, allowing for a quick recovery of the fleet. This attack brought America into the war, and Japan too.