Military Force and American Policy, 1919-1939
Justice without force is impotent. Force without Justice is tyrannical. We must therefore combine Justice with force.
FREDERICK THE GREAT once observed that "diplomacy without armaments is like music without instruments." There is ample evidence that Europeans accepted Frederick's dictum. American statesmen of the nineteenth century, however, often denied the theory that military force was an inseparable and legitimate part of foreign policy and denounced the European concept of Realpolitik. Early in the century they stated the principle that the sole purpose of military establishments was defense. Diplomacy should be backed by legal and moral sanctions only. In nineteenth-century America, largely isolated from disputes of the European continent, such a passive policy was practical as well as idealistic and served the nation's needs in defense and diplomacy. The nonmilitary approach to diplomacy gradually became a tradition.
With the twentieth century and a changed world, America grew more vulnerable to military attack and more involved in world politics. The logic of a diplomacy divorced from military force became less clear. Indeed, during the First and Second World Wars a nonmilitary policy was rejected in theory and in practice. During the long armistice between these conflicts, however, the traditional separation of diplomat and soldier was reaffirmed. For good or ill, American foreign policy returned to the traditional reliance on moral force and public opinion. Defense became the sole duty of the small military forces maintained during the interwar years.
The American nation heeded well the advice of Thomas