I came across an excerpt of a speech that Bonhoeffer gave at Fano, Denmark.
I find it to be relevant in a timeless way, cutting through the ages until now, where it is once again supremely important to recall:
There is no way to peace along the way of safety. For peace must be dared, it is itself the great venture and can never be safe. Peace is the opposite of security. To demand guarantees is to want to protect oneself. Peace means giving oneself completely to God's commandment, wanting no security, but in faith and obedience laying the destiny of the nations in the hand of Almighty God, not trying to direct it for selfish purposes. Battles are won, not with weapons, but with God. They are won when the way leads to the cross.
Bonhoeffer, Metaxas, p. 241