John J. McCloy was Assistant Secretary of War during World War II, and U.S. High Commissioner for Germany (1949-1952) during the period when the Germans were seen primarily as allies against Communism. Here we see McCloy, left, with Robert Kennedy.
After visiting Hitler's mountain retreat at Berchtesgaden in 1945, John F. Kennedy wrote in his diary that Hitler "had in him the stuff of which legends are made," and predicted that "within a few years Hitler will emerge from the hatred that surrounds him now as one of the most significant figures who ever lived." There is also a photo of McCloy with President Reagan, who famously drew Jewish ire by making a conciliatory speech at Germany's Bitburg Cemetery. Were the Kennedys and Reagan really "insensitive" or did they, like McCloy, simply not accept the propaganda-claims about which sensitivity was expected?*
"To be fair, the reports of genocidal crimes were so sweeping and so gruesome that a great many Americans, including some Jewish leaders, simply refused to believe them. As late as December 1944, [U.S. Assistant Secretary of War John J.] McCloy took aside the president of the World Jewish Congress, Leon Kubowitzki, and said, 'We are alone, tell me the truth. Do you really believe that all those horrible things happened?'" (Peter Wyden, The Hitler Virus (2001): p. 65)
Note that McCloy did not ask if the stories were true, or what evidence there was. McCloy was asking in effect if the president of the World Jewish Congress was as crazy as his statements. Do you really believe what you are saying?
It was McCloy who insisted that the German leaders be tried instead of being executed without trial. Although the International Military Tribunal at Nuremberg was a travesty of justice, it forced the conquering powers to state some kind of case, which is now a fertile source of embarrassment for those who maintain that the treatment given to the leadership of the Third Reich was just. If McCloy had not made the argument for trying those "war criminals," it would not have been possible years later for Professor Robert Faurisson to analyze the proceedings and note their deficiencies, e.g. that cross-examination on the question of gas-chambers had been omitted.
McCloy seems to have been one of those in the U.S. political establishment who understood that the Germans were being slandered with false propaganda, or at least had serious doubts, but did not dare to oppose it directly.