Japan-US Oil and Steel Embargo (World War II); Pearl Harbor attack

Here's a military externality. One of the major causes of bringing the United States into World War Two was the fact that we didn't like some of the things the Japanese were doing. They went into Manchuria, they murdered ten million people in Manchuria. We didn't think that was nice. There were other things they were doing. And we cut off their source of iron and steel scrap. They didn't have a big economy that was generating old metal parts. We did — we had the world's largest economy, and we generated more iron and steel scrap, we still do, than just about anybody in the world. China probably hasn't surpassed us, but they might surpass us in a few years. When we cut off the iron and steel scrap to Japan, we were basically like cutting off the oil to North Korea today. You can argue the Japanese had no choice and they bombed Pearl Harbor, because they were basically going to starve without the iron and steel scrap. We cut it off without thinking of what we were doing to them and whether they would get desperate enough to attack us.