【单选题】

War has escaped the battlefield and now can, with modern guidance systems on missiles, touch virtually every square yard of the earth’s surface. War has also lost most of its utility in achieving the traditional goals of conflict.Control of territory carries with it the obligation to provide subject peoples certain administrative, health, education, and other social services. Such obligations far outweigh the benefits of control. If the ruled population is ethnically or racially different from the rulers, tensions and chronic unrest often exist which further reduce the benefits and increase the costs of domination. Large populations no longer necessarily enhance state power and, in the absence of high levels of economic development, can impose severe burdens on food supply, jobs, and the broad range of services expected of modern governments. The noneconomic security reasons for the control of territory have been progressively undermined by the advances of modern technology. The benefits of forcing another nation to surrender its wealth are vastly outweighed by the benefits of persuading that nation to produce and exchange goods and services. In brief, imperialism no longer pays.

Making war has been one of the most persistent of human activities in the 80 centuries since men and women settled in cities and thereby became "civilized", but the modernization of the past 80 years has fundamentally changed the role and function of war. In premodernized societies, successful warfare brought significant material rewards, the most obvious of which were the stored wealth of the defeateD、Equally important was human labor--control over people as slaves or levies for the victor’s army, and there was the productive capacity--agricultural lands and mines. Successful warfare also produced psychic benefits. The removal or destruction of a threat brought a sense of security, and power gained over others created pride and national self-esteem.
War was accepted in the premodernized society as a part of the human condition, a mechanism of change, and an unavoidable, even noble, aspect of life. The excitement and drama of war made it a vital part of literature and legends.
According to the passage, leaders of premodernized society considered war to be ______.A．a valid tool of national policy
B．an immoral act of aggression
C．economically wasteful and socially unfeasible
D．restricted in scope to military participants