Don't they need a cause to fight to the death as they do? (I'm considering here that they are unique individuals as shown in the classical trilogy and not clones as the prequels had it). To fight so courageously and fanatically don't they need at least something to motivate them? I heard somewhere that their looks (i.e. helmets) were based on the German armies of WW2, but in WW2 the German armies were highly motivated by racial supremacy and charismatic leadership, they were fighting based on an idea that they were the most unique elite people of the word (which at the present is also what motivates a certain small state I need not mention). But what cause do the Storm Troopers have? And furthermore why do they sacrifice their lives for someone like Vader who treats them like they're nothing but disposable assets which he can kill and crush like ants when they disappoint him or outlive their usefulness?