Understanding Hitler and the Germans

The internal logic of the Nazi movement and the Third Reich is intertwined with that of Hitler: one cannot be understood without first considering the other. How did an individual with little education or culture, whose life until the age of 30 had been a series of failures, manage to impose his will on a large modern country before leading it into a military and moral catastrophe unique in history? The answer to this question begs another: can what happened in Germany happen again?