Militarism is not a precise term and its definition may depend on one's ideology or point of view, and one's judgment of it may be determined by its extent and form. Classic militarism, epitomized for most Americans by Wilhelmian Germany or pre-Hiroshima Japan, has few examples in the American past, but war and preparation for war influencing the country's society and having its support is increasingly apparent, particularly beginning in the last half of the twentieth century. This is not to say that the country has not engaged in war or military conflicts or that manifestations of militarism have not existed in earlier America. Nonetheless, general antipathy toward the military and a Congress keeping tight reins on military appropriations are readily apparent through the first century and more of U.S. history. In the beginning, the War Department (including naval affairs until 1798) had the secretary of war and one clerk and was considered in those early years, as recorded by Leonard D. White in his administrative history of the period, as a "difficult and unpopular department." A century later, although the size had changed, it was still unpopular with many people, including politicians and labor leaders like Samuel Gompers, who may have been remembering the Pullman Strike when he said, "Standing armies are always used to exercise tyranny over people."
While the early twentieth century may have begun to erode such views, it was World War II and the Cold War that brought significant changes to the country's diplomatic and military policies, symbolized by the great growth of the State and Defense Departments. The secretary of war and his clerk at the beginning of George Washington's administration grew by the beginning of the twenty-first century to about 90,000 civilian and military personnel occupying millions of square feet of office space in the Pentagon and numerous other federal and commercial buildings in the Washington, D.C., area. After World War II, Americans were willing to accept these changes because most of them no longer believed that isolationism was a viable choice for the United States, and many were convinced that there was a new totalitarian threat, similar in their minds to Hitler and Nazism. When events in Poland, Germany, Greece, China, and Korea seemed to confirm their fears, many Americans, perhaps influenced by Munich and the belief that appeasement was futile for stopping aggressors, accepted containment, deterrence, and a buildup of armaments with an ample supply of nuclear weapons. Through these policies the Cold War came to permeate American society.
While militarism, or at least the preparation for war, was clearly evident during the Cold War, its justification, if not all of its aspects, remained a subject of debate. For critics who blamed the Cold War on the United States by failing to recognize the Soviet Union's security interests, Washington's military response was dangerous, wasteful, tragic, with a mindset that continued into the post–Cold War era. For those who believed the Soviet Union posed a real danger to this country and its friends, the preparation for war was correct and need not be regretted. The requirements for the future, with its changing political arrangements and new technologies, remained open for even more concern and debate as evidenced by proposals, which continued into the twenty-first century, for a missile defense shield.