The latest Latin coup, in Guatemala, underlines the sterility of this method of political change. The loser, Gen. Efrain Rios Montt, was something of a loner, a professional soldier who broke the military establishment's rules and relied on younger officers and fellow members of his Protestant fundamentalist sect. The winner, Gen. Oscar Humberto Mejia Victores, is an organization man who has served all previous masters, including the corrupt Lucas Garcia and the eccentric Rios Montt without visible scruples. "Above all," Gen. Mejia Victores said assuming power, "it is necessary to preserve and fortify the unity of the army, maintaining the principle of hierarchy and chain of command." Think of it: a coup to maintain the chain of command.

Meaning perhaps to avoid one error committed by his predecessor, the new chief of state is keeping to himself his old position as minister of defense. Otherwise, he seems to be cut from the mold that has made the Guatemalan army the faithful servant of the country's landed ruling class. He was the officer who actually led the forces that, in the name of combating "the Marxist-Leninist subversion" killed thousands of peasants, mostly poor underclass Indians, during the Rios Montt period. These tactics made it politically impossible for the Reagan administration to follow its strategic proclivity and enlist Guatemala openly in the ranks of its Central American anti-Communist brigade.

Gen. Mejia Victores was scarcely in the palace when he announced he was ending some of the restrictions on civil liberties put in place by his predecessor. Almost by definition, however, no gesture that the reigning general can make with a stroke of the pen has much serious meaning. Nor is Guatemala's need a simple "restoration of civilian rule" according to the already agreed procedures which Gen. Mejia Victores has now said he may expedite. The country has a frail and archaic political system representing, or fronting for, a power structure born in a now-indefensible earlier age. It takes a vivid imagination to expect this general to undertake the long, difficult renewal that must come to Guatemala someday.

U.S. military aid to Guatemala ended in 1977, and already in some official quarters in Washington the argument is starting to percolate that a resumption of aid would enable the United States to soften military rule and meanwhile to enjoy the benefits of fuller strategic cooperation. The old general, it is suggested, was an odd fellow; the new one is "someone we can work with." It's a weak and distasteful argument. The United States has backed too many generals of the old school, in Guatemala and elsewhere, and there is no need to rush to take up another now.