Franz Jägerstätter was an Austrian conscientious objector during World War II. Jägerstätter was sentenced to death and executed for his refusal to fight for Nazi Germany. He was later declared a martyr and beatified by the Catholic Church.
Two quotes on the subject from people we all admire:
“I swore never to be silent whenever and wherever human beings endure suffering and humiliation. We must take sides. Neutrality helps the oppressor, never the victim. Silence encourages the tormentor, never the tormented.”
“Never be a spectator of unfairness or stupidity. The grave will supply plenty of time for silence.”
– Christopher Hitchens