Chileans must lead

THE tumultuous demonstrations raging through Chile this past fortnight against the dictatorship of Gen. Augusto Pinochet Ugarte suggest just how isolated he has become. A majority of Chileans representing a wide spectrum of political ideas from left to right are clearly angry with General Pinochet's 11 -year-old government. ''Pincohet must go!'' is now a populist chant in both the poor shantytowns of Santiago, the Chilean capital, and the affluent middle-and-upper-class barrios.

Although General Pinochet has successfully resisted vigorous calls for his ouster over the years - and could manage to do it again - this time the pressure seems to have built to the point that the real question is just how much longer he can hold on. Some of his closest advisers say privately that it cannot be more than a couple of months.

If Pinochet were to be overthrown, what then would be next for this land that in earlier, happier eras was regarded as Latin America's greatest democracy? And who would emerge to lead Chile in the months ahead? So far, there are no clear answers.

The armed forces, although long disenchanted with General Pinochet's rule, have failed to come up with one of their own to take the helm - and many military men are unhappy with the civilian alternatives.

For that matter, so are many other Chileans. This attitude pinpoints the failure of the civilians to coalesce behind a viable, effective alternative to Pinochet. The centrist Christian Democratic Party, Chile's largest, is much divided between left and right wings. The more conservative National Party, the amalgam of traditional political parties from the last century, has its own serious divisions. On the left, the Socialists, Communists, and other smaller, radical groups, are squabbling. The situation is clearly ripe for demagoguery - and continued turmoil.

Many Chileans worry that a new dictator could emerge from the current disarray and the possible political vacuum following a Pinochet ouster. A right-wing authoritarian regime is one possible scenario, while another is a radical leftist takeover that would prove just as onerous. To prevent either of these possibilities, there is some movement among the citizenry toward the idea of moderate political leadership, perhaps in the person of the diminutive Andres Zaldivar Larrain, an internationally respected Christian Democrat. So far, however, this effort hasn't made much progress.

Nor has international pressure against the Pinochet government to alter its heavy-handed dictatorship borne much fruit. The United States, long critical of the Pinochet rule, has sought to encourage both a movement toward democracy in Chile and a lessening of the military heavy-handedness but without great success. It is unlikely that further efforts in this direction would yield positive results at this time. It now is up to Chileans to sort out their immediate future and to work to bring about a reasonable, moderate succession to General Pinochet.