SIETE DIAS, an important Argentine newsmagazine, has President Carter on its cover this week-along with pictures of policemen stomping on the heads of blacks in Philadelphia and helmeted troops allegedly shooting at rioters in an unidentified U.S. city.

Parati, a leading women's magazine, recently began urging housewives to send postcards with Argentine Flags to foreign critics of the military goverment's anti-terrorist effort and human rights record. The war has ended in Argentina," the post cards say. "They flags are symbolic of the peace that we have won."

The two magazines reflect a change of mood in Argentina which in the past has suffered international criticism largely in silence. In recent weeks, as Argentines back in the glory of staging and winning the World Cup soccer championship in June, they have begun to strike back. There has tionalistic spirit that has been a factor, in Argentina political life since Juan Peron first came to power at the end of World War II.

The new military has appeared at a time when U.S.-Argentina relations are at their lowest ebb in years, according to diplomatic observers, and seem likely to get worse if the Argentines do not improve the human rights situation and if the United States does not stop giving hardliners the opportunity to convince the people that the whole world is against them.

The Siete Dias issue with Carter's likeness on the cover carries an article that notes that terrorists, militants and common criminals in the United States are not always treated gently. "The United States today," reads the headline over a picture of soldiers aiming guns at a terrified black woman. "Mr. President is this the bulward of human rights?"

The article and pictures appear to be part of a growing government campaign against critics abroad who have accused the two-year-old military regime of President Jorge Videla of kidnaping, torturing, jailing and executing thousands of Argentines in pursuing its war against terrorism.

The Argentine military is portraying international criticism of its anti-terrorist campaign as criticism of the country itself. At the same time, the press is fanning the flames of nationalism among the country's 25 million inhabitants, who, for the most part, are ignorant of the kidnappings being carried out by secret anti-terrorist squads.

These secret police activities are not reported in Spanish-language newspaper, although the English-language Buenos Aires Herald does report missing person cases when families or friends provide information.

Average Argentines, however, are informed only when a prominant person disappears or when the terrorists strike, as they apparently did Aug. 1 at the home of Admiral Armando Lambaruschini, who will become the Navy's representative on the three-member ruling junta next month.

Lambruschini was not home when a bomb exploded in an apartment adjacent to his but his 15-year-old daughter, was killed. The bombing received front-page coverage and revolted many Argentines.

A week after the bombing, Patricia Derian, the U.S. State Department's top human rights official, sharply criticized the Argentine government in testimony before a House of Representatives subcommittee in Washington.

Derian accused the Videla government of "systematic torture" and "summary executions" of terrorists and political opponents and said there was no indication that the human rights situation here is improving. Derian rejected the government argument that its anti-terrorism campaign is the result of the terrorists' activity, saying that Videla himself has said that the war against the terrotists has been largely won.

"It is ridiculous to violate human rights to protect human rights," Derian said. This statement infuriated government supporters, who argue that there is no way to stop an estimated 20,000 active terrorists and their backers except to fight them with extralegal and clandestine methods similar to their own.

The day after Deritns testimony, the Foreign Ministry issued what government officials and diplomats describe as the strongest and U.S. statement in recent memory. The statement expressed "indignation" calling Derian's statements "false and tendentious, an offense to the Argentine people and harmful to ties between both states."

The Foreign Ministry statement seems to have been a signal to a host of military men, retired and active, to therefore no reason to control the anti-terrorist squads. Some generals, it is believed, would like to unleash the secret police against all present and former Peronists and Leftists, regardless of whether they ever engaged in terrorism.

Those Argentines who are particularly interested in maintaining and take up the cry against foreign critics. Almost every day for the past two weeks, there has been a speech, an editorial a television commentary or a feature - critical of Derian in particular or of foreign critics in general. The argument is usually the same: the foreigners do not understand what the situation was like two years ago when the military overthrew the government of Isabel Peron, and are totally unfair when they criticize the anti-terrorist campaign without criticizing the terrorists.

The U.S. position has been that Videla and other so-called moderates in the government are not doing enough to improve the human rights climate or to restrain the extralegal anti-terrorist squads.

But there is a growing fear, in business and legal circles, that anti-U.S. feelings within the military could lead to aggreement that there is no way to placate the Carter administration, and strengthening relations with the United States worry that the Carter administration is exhausting its influence with the Argentine military despite the work of U.S. Ambassador, Raul Castro, who is generally given high marks for his efforts to keep the diplomatic situation from getting out of control.omatic situation from getting out of control.