Couldn’t agree on territory borders
It was "Russia" that was the last to industrialize, since while most of nations were going through the industrialization process, Russia was in the middle of various uprisings that eventually led to the Civil War of 1917.
Hitler, Mussolini, Stalin, and Trump all used propaganda and fear mongering to emotionally and mentally manipulate supporters into giving them more power and discriminate and attack people with opposing views
They believed in gods and goddesses so they could count on someone to help life go smoothly.