As Chile's neighbors restore civilian rule, its own leader, Gen. Augusto Pinochet Ugarte, is increasingly isolated and defiant. ''There will be no change in our plans to hold elections in 1989,'' he said last week in the wake of bitter street demonstrations against his 10-year rule. ''The timetable is set. Period. We will not change.''
But more and more Chileans are joining in the clamor to end General Pinochet's hold on power. They note that Argentina plans to hold presidential elections in October, and that other neighbors are returning to civilian rule.
Street demonstrations in Santiago, Chile's capital, in recent weeks are merely the tip of an iceberg of growing discontent.
General Pinochet has been buffeted by a rising current of discontent over the years. This time, however, the protests appear stronger and more determined. Moreover, opposition appears to be spreading into the once-monolithic armed services.
Air Force Gen. Fernando Matthei, 1 of 4 members of the military junta, seemed to break with his fellow commanders, including General Pinochet, when he said Friday: ''It is time for us to come to an understanding with the political party. . . . It is time for Chile to open a political debate.''
Actually, the Air Force has never been happy about continuing military rule, much less being a part of that rule. Gen. Gustavo Leigh Guzman, the first Air Force officer on the junta, was forced off the junta over his outspoken views, which Pinochet correctly interpreted as opposition. But the Matthei views are regarded as perhaps even more significant because he had earlier been seen as quite willing to accept the Pinochet rule.
''He's the last person you'd expect to rock the boat,'' said a Chilean military source.
How much rocking of the boat he has done remains to be seen. The government was already reeling from protests staged last May - and even more so by demonstrations last Thursday, which continued into the weekend.
People from all classes and all walks of life - from the poor to the rich, the jobless to the employed - took part in last week's protest. The government called out 18,000 troops to quell the protests, which surfaced in the peaceful banging of pots and pans from apartment windows in a symbolic protest over food shortages, hunger, and unemployment as well as in bonfires and street demonstrations.
The police and Army units took particular aim at university students, storming buildings at the University of Chile. They threw tear gas and stones, and fired automatic weapons at the youthful demonstrators, who by most accounts were peaceful in their protest. The government Thursday reimposed a 6:30 p.m. curfew on Santiago (it was lifted four years ago) and began arresting people on the streets after that hour. By week's end an estimated 1,500 persons had been arrested.
It is not overlooked by Chilean observers that pots and pans were banged before civilian President Salvador Allende Gossens was ousted by the military on Sept. 11, 1973.
With that anniversary drawing near, politicians again are calling on Pinochet to step down. They do not want to wait until 1989 for a power shift. The nation's Constitution, engineered by Pinochet, calls for him to stay in power until 1989.
The Christian Democratic Party, Chile's largest, is calling for an end to Pinochet's rule. Gabriel Valdes Subercaseaux, the party's president, said, ''It is high time that the military recognize that they have no support among the civilian population.''
There were hints that he had been in touch with Air Force officers, perhaps even General Matthei, but there was no confirmation.