It was Bonhoeffer who wrote The Cost of Discipleship. Bonhoeffer also joined the Confessing Church movement but he had moments where he didn't think too clearly at times kind of falling into an eastern religious pacifist mentality. Reinhold Neibhur did however show Bonhoeffer where his theology was off track at those times.
You are so very correct...my brain must be set to old age today...I offer my most humble apologies for such an egregious error. I am not worthy...bowing deeply