The Devil's General.

The adaptation of the eponymous play by Carl Zuckmayer tells the story of renegade general Harras of the German Luftwaffe, who during WWII openly criticizes the Nazi regime. As a consequence, he is put under surveillance, and even imprisoned for a brief period of time. Still remaining outspoken, Harras realizes the horrific dimensions of this hopeless and injust war waged by Germany.