the Rote Kapelle spy network were traitors. Ritter wrote that those involved in the Rote Kapelle were not part of the "German Resistance, but stood in the service of the enemy abroad" and so fully deserved to be executed. Ecumenical progression Besides defending German nationalism, Ritter became active in the ecumenical movement after 1945 and urged conservative Catholics and Protestants to come together in the Christian Democratic Union. He argued that based on his experience in Nazi Germany, Christians, regardless of their church, needed to work together against totalitarianism. During the war, as a result of his underground work, Ritter came to know a number of Catholic and Calvinist members of the German opposition, which caused Ritter to abandon his former prejudices against Calvinists and Catholics. Ritter came to the conclusion that whatever differences divided Lutherans, Catholics and Calvinists, member of all three churches had more in common to unite them against the Nazis. Goerdeler biography In 1954, Ritter published an acclaimed biography of Carl Goerdeler, a close friend, a conservative politician who was executed by the Nazis in 1945. Goerdeler was a devout Lutheran and the son of a conservative Prussian politician. Ritter pushed for the translation of his Goerdeler biography into English to counter the publication of John W. Wheeler-Bennett's book Nemesis of Power, which in his view vilified the German resistance. German militarism Ritter specialized in German political, military and cultural history. Ritter always drew a sharp distinction between what he regarded as the Machtpolitik (power politics) of Bismarck in which military policy was subjected to carefully limited political goals and the endless expansionism that was motivated by militarism and bizarre racial theories of the Nazis. Ritter was well known for his assertions denying that there was a uniquely-aggressive German version of militarism. For Ritter, militarism was the "one-sided determination of political decisions on the basis of technical military considerations" and foreign expansionism, and it had nothing to do with values of a society. In a paper presented to the German Historical Convention in 1953, "The Problem of Militarism in Germany", Ritter argued traditional Prussian leaders such as Frederick the Great were Machtpolitiker (power politicians), not militarists, since in Ritter's view, Frederick was opposed to "the ruthless sacrifice of all life to the purposes of war" and instead was interested in creating "a lasting order of laws and peace, to further general welfare, and to moderate the