When political decisions are out of the hands of the public, popular ideas about how those decisions are made are likely to be astoundingly wrong. That so many Americans still believe that this country's military presence in Vietnam was the consequence only of accidents, miscalculations, and basically benign intentions is the most striking recent example.

Such popular misconceptions are strengthened by the mass media's failure to place contemporary events in a larger historical context. While the forms of American expansionism have changed over the past 200 years, and several major shifts in the ideology surrounding U.S. imperialism have occurred, it is possible to trace this history of change systematically.

Each era of expansionism has had its own popular slogan--from "Manifest Destiny" to "Open Door" to Henry Kissinger's "Stable Structure of Peace." The aim of foreign policy nevertheless remains the same--the establishment of what John Adams in 1774 called "an independent empire."

During the 20th century, Americans have resisted calling themselves imperialists because of the nonterritorial nature of most U.S. economic and political expansionist plans. "Empires" are thought to be systems of colonies such as those of Britain and France. The United States is supposedly interested only in the diffusion of political democracy and free enterprise, its economic counterpart.

But the history of 19th century U.S. expansion is precisely a history of territorial takeover beginning with a revolution which, if anything, diminished the prospects for self-determination among non-white oppressed groups in North America.

To dispell the mythology of the revolution is necessary to destroy at least one popular image of U.S. expansionism: the picture of the United States, the first liberated colonial territory, likewise spreading liberation through its intervention in the struggles of other states. American colonists had not been the lackeys of British entrepreneurs. They were mercantile partners rebelling against fetters on their independent economic development, a future which many colonists anticipated would include taking over the West.

The chief limits upon early 19th century expansionism were economic; not until the 1840s could the United Stated be considered industrial. Inevitably, the construction of direct economic links between North and West with new developments in railroads and communication disrupted the delicate balance between the industrial North and the agrarian South and West which had held the early Union together.

Once the North had won the Civil War, the direction of future expansion, both in the West and overseas, was set. Markets, outlets for investment and, secondarily, sources of raw materials were what the North wanted, not slave labor territories to support a landed upper class.

The great problem arose once the United States reached the Pacific, and the territory that it had been her "manifest destiny" to occupy had been taken. Half of the 25-year period between the end of reconstruction and the Spanish-American War were years of depression. Workers employed in railroad construction were being laid off. With the completion of the national railroad system and the industrialization of agriculture, both heavy industrialists and large commercial farmers were looking anxiously for markets. The traditional outlet of westward expansion appeared closed.

Eastern capitalists had looked to China as a possible overseas outlet for profitable investment and commodities since the 1840s. Under Secretary of State William H. Seward, the United States purchased Alaska and annexed the Midway Islands as stepping stones to Asia in 1867.

But few were active proponents of a military empire. The costs of a worldwide standing army were prohibitive. Nor was it clear that such a burden of funds and responsibility was necessary.

Historians have rightly insisted that U.S. expansionist efforts cannot be explained along the lines of a strict cost-benefit analysis of businessmen's profits. Social conditions in the late 19th century just as domestic unrest today established the context within which expansion might be pursued.

But historians have also underestimated the economic foundations of foreign policy. The United States did not trip unwillingly into the arena of world power in the 1890s. Given the country's economic needs, the reorganization of the national economy into a system of finance capitalism, and the extent of social chaos deepened by the calamitous depression of 1893, the form and extent of U.S. intervention in Cuba and in the Far East in the late 1890s are understandable.

U.S. economic policy hastened Cuba's drive for independence. As European beet sugar production drove the price of Cuban sugar down, Americans stepped in where plantation owners were selling out cheaply. An increase in the U.S. sugar tariff in 1895 accelerated the rate of plantation workers' layoffs, heating up the Cubans' resentment of Spain to the point where revolution was inevitable.

U.S. economic groups with no interests in Cuba naturally opposed this country's intervention in 1898. But U.S. participation served not only to mollify a public frightened by the growing pains of capitalism--labor violence, the concentration of ownership, urbanization, the dissolution of "rural values," and the swelling number of non-English speaking immigrants--it also bolstered moderate and conservative elements among the revolutionaries, preventing Cuba from falling into the hands of militant nationalists. Limited intervention became a legitimate foreign policy instrument.