Argentina's new military government has clearly signaled that U.S.-Argentine relations after the Falkland Islands crisis will return to the condition of verbal friendship and practical contentiousness that have characterized them in the past.

President Reynaldo Bignone and the conservative Army leadership have firmly outlined their intention to halt the swing toward partnership with the Cuba-led nonaligned nations group initiated by ousted president Leopoldo Galtieri at the height of the conflict with Britain.

But while insisting that Argentina will remain a "Western" country, Bignone and the new foreign minister, Juan Aguirre Lanari, have also made clear that they now share few of the plans for a close alliance with the United States that was the most celebrated feature of Argentine foreign policy earlier this year. Instead, Aguirre Lanari said in a speech yesterday that Argentina will be "dedicatedly independent, the jealous custodian of its own capacity of self-determination." What that means, Argentine officials here explained, is that Buenos Aires will be what it almost always has been: parochial and pragmatic to an often bewildering extreme, enmeshed in a series of loose and often contradictory alliances that have permitted it to be fiercely anticommunist, nonaligned, pro-Western and anti-Yankee all at once.

For the Reagan administration, the return to traditional Argentine foreign policy will mean the loss of what had been grand plans--at least in Buenos Aires--for regional cooperation between the two countries.

Before the invasion of the Falkland Islands April 2, the Galtieri government was considering a range of measures to strengthen relations with the United States, including a loosening of ties to Cuba and Nicaragua, cooperation on such issues as sanctions against Poland, and active military participation in U.S. projects in Central America, according to sources and documents available here.

Now, Argentina is likely to return to the course that over the years caused it to attempt to block almost every regional U.S. initiative, to refuse to participate in the Sinai peace-keeping force or sanctions against Poland, and to increase grain sales to the Soviet Union during the 1979 U.S. embargo.

Even this kind of pragmatic neutralist policy has become the subject of controversy within some civilian and military circles. The government's opponents maintain that Argentina should break its relations with the United States and Europe while conducting a continuing campaign of harassment against Britain in the Falkland Islands.

In this sense, Argentine analysts say, an important element of the political struggles around the Army government is likely to be whether a return to cordial relations with the United States benefits Argentina on the overriding issue of the Falklands.

Aguirre Lanari and other government officials, conscious of being considered pro-Washington, have pointed to this issue, saying that future U.S.-Argentine relations will depend on "concrete acts" by the United States.

In a letter to President Reagan responding to a congratulatory note on his inauguration, Bignone said that good relations between Argentina and the United States are "a desirable object" for his government but that progress in this direction is being impeded because "the United States persists in maintaining even now the coercive economic measures" imposed during the Falklands conflict.

What the Bignone government now expects from the United States, officials say privately, is not only a lifting of the sanctions but a move by the Reagan administration to reduce its support of Britain and apply pressure for negotiations on sovereignty over the Falklands.

Without such assistance, these officials warn, and with the Falklands remaining a fortified colonial garrison off Argentina's southern coast, the Bignone government may be forced to adopt a radical policy line.

"We are not asking anything from the United States," said one ranking government official, who asked not to be named. "But if the U.S. wants to keep their relations with us, they will help on this."

This government attitude differs little from Galtieri's view at the time he became president and leader of the ruling junta last December. Galtieri's advisers outlined a program of cooperation with the United States that would have been nearly unprecedented in Argentina's isolationist history.

But all along, Galtieri, former foreign minister Nicanor Costa Mendez and other officials appeared to assume that their strategic cooperation with the United States would gain them assistance on Argentina's traditional parochial interests--particularly the Falklands claim.

The expansiveness of the policy and the Army government's misjudgments of the United States are indicated in a document drawn up early this year and submitted to Galtieri by his influential Army representative in Washington, Gen. Miguel Mallea Gil.

The policy plan, a copy of which was obtained by The Washington Post, suggests actions ranging from inviting a host of Reagan administration officials to Argentina to hiring a public relations firm in Washington to help Argentina "realize political objectives with greater ease."

Several of the recommendations had been acted upon when the dispute with Britain arose. For example, Argentine ambassadors in Cuba and Nicaragua were recalled amid suggestions that they would not be returned.

In addition, the plan suggested consideration of measures "to inhibit the action of Cuba and Nicaragua in El Salvador" "in case our collaboration is requested." Argentina was subsequently reported to have sent dozens of advisers to Central America to help train paramilitary forces in collaboration with the United States.

By the end of the year, the plan envisioned an Argentine policy that would have been closely linked with that of the United States, including even the making of foreign aid grants "where we can have a coincidence with the U.S." and the linking of Argentine and U.S. political operations in Bolivia, where both countries have strong influence.

But Argentine officials appeared to see the benefits of this policy not as much in regional strategic terms as in traditional "political objectives" such as the occupation of the Falklands. Argentine officials now concede that they expected the United States to be a favorable influence on Britain after the invasion of the Falklands, and Mallea Gil has been widely reported in political circles close to the military as having reported to the junta that the U.S. reaction would be far milder than it was.

In a telephone interview, Mallea Gil, who remains in Washington, acknowledged the existence of the policy document but refused all comment.

With the U.S. support for Britain in the Falklands crisis and Argentina's subsequent military defeat, most of the plans for cooperation with the United States now appear to have been at least temporarily abandoned. Appointment of a new ambassador to Cuba is under consideration, and political sources close to the military say about 70 Argentine advisers in Central America have been withdrawn.

Instead of actively seeking a close alliance and its benefits with the United States, Bignone's government has signaled that it will wait for Washington to make its own gestures of good will, not on broad issues, but on the specific interests like the Falklands that have always mattered most here.

Meanwhile, while generally aligning itself with the West's strategic interests, Argentina is likely to adopt foreign-policy measures on the basis of immediate nationalistic interests, rather than any broader interests or plan.

"We are determined to preserve our style of life, inspired by fundamental values like liberty, justice, and democracy," Aguirre Lanari said in his speech yesterday, "just as we are equally decided to defend, with the most unbreakable determination, our national interest, whose most notable expression is the preservation of the territorial integrity of our country and the independence of its decisions."