Hans J. Morgenthau...Don't even try to read this article.

The political scientist Hans J. Morgenthau did more than any other figure to establish the realist interpretation of international affairs. In 1948 he published his classic treatise Politics among Nations: The Struggle for Power and Peace, which argued that struggle for power was the essence of international affairs. Born in Germany in 1904, Morgenthau fled to Switzerland to escape Hitler and in 1937 emigrated to the United States, where he found the study of international affairs disorganized. While teaching at Brooklyn College, later at the University of Kansas and, beginning in 1943--the year he became a citizen--at the University of Chicago, he criticized the writing in his field by historians and international lawyers as overly legalistic and idealistic. Morgenthau brought from the Old World a pessimism about man's nature and the state of the world, while his scholarly work led him to believe that objective truths about politics could be discovered by human reason. His wealth of knowledge enabled him to lecture to his classes on world politics without a text; one of his students took a stenographic transcript of what he said, which became the draft of his book.

Morgenthau directly related his power theories to the observation that "the United States is at the moment of this writing the most powerful nation on earth." He was intrigued with the problems and rivalries this power created. "International politics," he wrote, "like all politics, is a struggle for power." Power was more than brutal force, it was the central aim of national interest. He proposed that the pursuit of power was the source of state behavior. No matter what the ultimate aims of nations, whether freedom, security, or prosperity, their immediate goal was power. Power was the means to national ends. Political power meant "man's control over the minds and actions of other men." It followed that power was also "a psychological relationship between those who exercise it and those over whom it is exercised," enabling some people to control the actions of others through orders, threats, persuasion, or a combination of these. Since he had traced the struggle for power back through history, he believed the contest for power must be ever-present.

Morgenthau, impatient with moral sentiment or wishful idealism, believed that the pursuit of power was not necessarily immoral. "To act successfully," he wrote in Scientific Man vs. Power Politics in 1946," ... is political wisdom. To know with despair that the political act is inevitably evil, and to act nevertheless, is moral courage. To choose among several expedient actions the least evil one is moral judgment. In the combination of political wisdom, moral courage, and moral judgment, man reconciles his political nature with his moral destiny."

The chief opponents of the realists were the humanitarian moralists who saw the world from a different, ethical perspective. Of a longstanding tradition in the nineteenth century, the moralists included philosophers and writers who attributed America's rising world influence not to external force but to the internal example of a society. They opposed the power politics and imperialism of Europe. One of the early, clearsighted moralists was Albert Gallatin, who wrote "The Mission of the United States" at the time of the Mexican War. "Your mission was, to be a model for all other governments" and "to apply all your faculties to the gradual improvement of your own institutions" and, "by your example, to exert a moral influence most beneficial to mankind at large. Instead of this, an appeal has been made to your worst passions; to cupidity, to the thirst of unjust aggrandizement by brutal force; to the love of military fame and of false glory." Aware that the world powers of the past had been empires and monarchies, the moralists argued that the United States should not act imperially in emulation of them but rather show the way to reform by exhibiting the success of its democratic society. Morgenthau pointed to John C. Calhoun and William Graham Sumner as worthy representatives of this world perspective, the latter writing during the Spanish-American War that "expansionism and imperialism are at war with the best traditions, principles, and interests of the American people."

The realists responded that in the past the moralists could afford to advocate that their nation be small and inconsequential but virtuous. After all, they had lived on a continent insulated from the outside. But their legacy threatened to damage the national interest, which required growing world involvement. Even when leaders made decisions for "realistic" actions, the realists contended, they had been perverted by irrelevant moralistic justifications. A case in point was President McKinley's defense of colonizing the Philippines: after prayer in the wee hours of the morning, he revealed, he had heard the voice of God tell him to annex the islands.