The appeasement of Nazi Germany at Munich in 1938 has cast a long and enduring shadow over international affairs and the debate about pacifism. According to conventional interpretations pacifism led to appeasement and isolationism, which left Britain and other countries vulnerable to fascist aggression. Walter Lippmann wrote, “The preachment and the practice of pacifists in Britain and America … were the cause of the failure to keep pace with the growth of German and Japanese armaments. They led to the policy of so-called appeasement.” Reinhold Niebuhr held similar views. “Nazi tyranny was allowed to grow … because so many citizens of a Christian civilization were prevented by these (pacifist) scruples from resisting the monster when there was yet time.” Neville Chamberlain was forced to yield to Hitler's demands, according to this view, because of the pervasiveness and influence of pacifist pressure. Variations on this theme have permeated debates about war and peace ever since. In August 2006 US Defense Secretary Donald Rumsfeld evoked the memory of appeasement to challenge critics of Bush administration policy in Iraq. The world today faces “similar challenges in … the rising threat of a new type of fascism,” Rumsfeld claimed, warning that “some seem not to have learned history's lessons.”

The claim that pacifists were responsible for the political vacillations and mistakes that led to World War II is profoundly mistaken.