Argentina's military rulers today marked the fifth anniversary of Operation Independence, the code name for the first phase of their war against subversion, amid clear signs that the government has decided to tacitly admit its responsibility for the thousands of Argentines who have disappeared and died since 1975.

The first signal of what would be a sharp policy change, and a victory for moderates headed by President Jorge Videla within the military came Tuesday when the Foreign Ministry permitted publication here of the State Department's report to the U.S. Congress on the human rights situation in 154 countries.

The report on Argentina painted a grim account of the conditions that led to the military's decision to undertake an all-out campaign to rid the country of left-wing terrorism. This campaign led to serious human rights abuses, including torture, disappearances, summary executions and thousands of ostensibly innocent political prisoners who spent years waiting to be charged and tried.

The second sign of the government's policy change came yesterday when Videla's office issued a statement saying that only the Argentine people "have the right to judge the situation in light of the current state of peace and security," in effect an acknowledgement that a human rights "situation" exists.

The Argentine statement did not deny that serious rights violations have occurred here but asserted that the military's antiterrorist campaign was begun only "as a consequence of the war launched by the terrorist organizations" about six years ago.

Until this week, the government had specifically and repeatedly denied responsibility for those who had disappeared, estimated at between 8,000 and 20,000, saying they either had been killed in confrontations with the military or police, had gone underground or had left the country without notifying their relatives, who then reported them missing. The military also denied that operatives under its controls used torture as a means of obtaining information.

By distributing the U.S. report on rights, the Argentine government ensured that it would be reproduced in full by country's newspapers here. Although the Foreign Ministry then protested, in a note handed to U.S. Ambassador Raul Castro, that the report was "an intrusion into the internal affairs" of Argentina, the country's 26 million people were given the opportunity of reading a document that detailed the methods used by the military to combat the 4,000 to 5,000 guerrillas active here in 1974.

"There is substantial evidence that most of [the missing] persons were abducted by the security forces and interrogated under torture," the U.S. report said. "As most have not reappeared, many observers believe that they were summarily executed. There have been reports, difficult to verify, that some missing persons have been seen alive in detention centers."

Since the report was published, the government and those members of the armed forces who have commented on it have carefully avoided saying that the charges are not true. Many diplomatic and Argentine observers have concluded that the government is deliberately using the U.S. report to bring into the open the rights abuses that have occurred.

The influential Buenos Aires Herald, in an editorial entitled "Biting the Bullet," said distributions here of the report "marked the official beginning, as it were, of a process of self-examination through which the country will have to pass if it is ever to have a chance of becoming a stable democracy."

Another possible factor is the imminence of a report by the Inter-American Commission on Human Rights that is expected to name individuals held responsible for rights violations. It is thought that the publicity given now to the U.S. report may serve to cushion the impact of the more detailed findings later by Organization of American States group.

It is known that the decision to release the U.S. report here has angered hard-liners in the military, especially the younger generation of colonels and captains who are thought to have ordered the torturing and killing and who may now feel the generals are abandoning them in bringing the past into the open.

Many observers say it is unlikely that the generals will admit publicly that they used the methods described by the State Department and human rights groups -- torture and summary executions. They seem to have decided to leave that apportioning of responsibility to the State Deparment.

However, Army Commander and ruling member Gen. Leopoldo F. Galtieri, in a speech marking the fifth anniversary of Operation Independence, said:

"As citizens, as parents and as soldiers, we can and should understand the legitimate pain of those of our countrymen who have no explanation for the death or dissappearance of a loved one. We understand this and it worries us but, nonetheless, we cannot explain the inexplicable or give the reason to that which is irrational."