It all goes back to Gavrilo Princip, assassinating Archduke Franz Ferdinand of Austria, setting off the chain of events leading to WWI. Post WWI, France and the UK fucked up the land/power struggle in the Middle East with the Asia Minor Agreement. Germany got fucked over by the war guilt clause of the Treaty of Versailles. So post-war Germany inevitably props itself back up with the help of the Nazi party, and we have WWII. Meanwhile the US is exporting war supplies to China, and Japan invades, trying to embargo any imports into China. The US responds by placing an oil embargo on Japan, so Japan attacks Pearl Harbor in an attempt to control oil in the Dutch East Indies. As a result of dipping their capitalist toes in the wars of other nations, the US declares war on Japan, and Germany declares war on the US. Roosevelt dies too early, and Truman cranks us into fifth gear by flaunting nukes so he could grab that sweet middle eastern oil out from under Russia, starting the cold war. Now we're saving the world from communism while the CIA is simultaneously installing a puppet government in Iran. And to stay on good terms with Saudi Arabia for their oil, we give them tons of military assistance so they can funnel it into Wahhabist education.

And their was probably some shit before that too.