Argentina democratic government is once again under attack from the violent and unreconciled supporters of the military junta that collapsed two years ago. The current epidemic of bombings is apparently not designed solely to disrupt the congressional elections next Sunday. The bombers are trying to prove that democracy won't work in Argentina and that, to restore order and security, the country will have to return to the previous style of authority.

Until last spring, friends of the junta could hope that inflation would do their work for them. President Alfonsin was following a cautious and hesitant economic policy that was proving increasingly ineffectual. By late spring the economy was sliding toward hyperinflation, an experience that democracies rarely survive. But in June the Alfonsin administration imposed a totally different and more drastic plan -- and, so far, it has proved extraordinarily effective. The inflation rate fell from 31 percent a month in June to 6 percent in July and 2 percent in September, as industrial production began to rise again.

Meanwhile, the government had brought to trial nine generals and admirals of the former junta, and throughout the summer there was an outpouring of testimony describing the violations of human rights under their rule. It's a remarkable case, for three of the defendants are previous presidents of the country. There was much doubt earlier that the government would ever be able actually to prosecute these men. But the trial is now concluded and a verdict is expected shortly. The bombings this month are a response to the successes of a popular government, not to its failures. Because the junta's friends find themselves more isolated than ever, they have resorted to the tactics of terror.

The Alfonsin government arrested a dozen prominent suspects last week, but a disagreement arose among the courts over its authority to hold them. As judges began to free some of them, Mr. Alfonsin decided to impose the state of siege -- suspending certain civil liberties -- for 60 days.

He is presiding over a country badly shaken by the savagely divisive and destructive politics of the past generation, and in many Argentines' minds the basic question is whether it can be ruled by any instrument but the gun. Mr. Alfonsin stands for a better alternative, but he has felt himself compelled to take a step backward. His defenders can point out that none of the government's extraordinary powers is being used to interfere with the election campaigning. It is always dismaying to see an expedient like a state of siege invoked, but Mr. Alfonsin has earned a presumption that he is proceeding in good faith.