Even though they were isolated, the one thing they did know, is that some countries were invading others, basically empire building. They were afraid that they might be attacked so they built a strong military and went on their own empire building initiative and invaded other countries like China trying to beat other countries to the punch. Although Japan was being attacked around the world for invading other countries, they were doing what other large countries like Britain, France, and Spain were doing so they were being treated with double standards.
But what was legitimate is the outrage over how they were empire building in that they were treating their enemies horrifically not at all following international laws (Geneva Convention 1864), about humane treatment of both combatants and non-combatants. Thousands of years of being programmed that the rest of the world was evil led them to believe that their enemies were just animals. Since the Emperor didn't access radio or television, he wasn't aware of the extent of the atrocities being committed by Japanese soldiers.
When Japan surrendered to us in 1945, General Macarthur and a team of investigators went to Japan to weed out war criminals. Some of these criminals committed suicide before they could get to them and many of the others they did find, were hanged. The investigative team was trying to figure out who authorized the war and who decided to end it. They weren’t going to set foot into Emperor Hirohito’s palace, since it was considered holy ground, until they knew if he was guilty of war crimes and they were surprised to find out that he wasn’t.
The Emperor was a man of peace, but the military forced Japan’s agenda. When he tried to get a message out to end the war, the military made six attempts to storm his palace and stop him from surrendering. The citizens who pretty much worshipped him, had no idea what the military was doing to take the Emperor out. He hid in the basement along with other supporters and when he came out, he sent a radio message to Japan’s citizens that they were to put down their arms and work peacefully with the U.S.
In the end, General Macarthur exonerated the Emperor and they agreed to work together to rebuild Japan. After the war, Hirohito removed the notion of a god status with his people. The U.S. and Japan accomplished the greatest rebuilding project in history and now Japan has the fifth largest economy in the world and are a leader in automobiles, computers, medical equipment, steel, etc.
Hirohito ended up being a very good man and a tremendous ally to the U.S. He remained Emperor until he died in 1989, having been the Emperor for 62 years. Hirohito was married to his wife Princess Nagako for 65 years and she died in 2000 at the age of 97. They had five children.