Bonhoeffer et al wanted to cut the head off the dragon I believe. The problem is that God is not willing that any should perish, according to Peter. God also said our enemy is not flesh and blood. So, aiming for Hitler as the head was a misfire all ’round. Hitler was only the flesh and blood puppet of our spiritual enemy (ies) as stated in Ephesians 6.
That is why God instructs us to pray for our enemies, to bless those who curse, etc. The heaping coals melt off the dross leaving no ground for bitter roots.
Let’s fight the real battle. Come on! *motions for you to join as she turns to run into the fight sword (of the spirit) held high, shield up, shoes tied on fast, helmet in place