The United States is giving Bolivia $36 million in foreign aid this fiscal year, a sum intended in part to help that Andean country return to civilian rule after a decade of military dictatorship.

Yet, three weeks ago, the Carter administration announced a step that could cost Bolivia as much as $60 million this year - A loss that government of President Hugo Banzer says could seriously disrupt Boliva's economy and fragile politics as well.

That wasn't what President Carter intended when he gave his support March 9 to a plan for the U.S. government to buy $250 million worth of copper and finance the purchase by selling 50,000 tons of government-owned tin. From Carter's point of view, that seemed like a savvy political thing to do.

What was applauded at home, however, evoked cries of "economic aggression" in places like Malaysia and Bolivia, that live off their tin exports. Outside the U.S. embassy in La Paz, it triggered an angry demonstration led by Juan Pereda Asbun, who is regarded as the front-running candidate for the Bolivian presidency.

These differing reactions illustrate the head-on collisions that confront the Carter administration whenever it has to deal with raw materials, prices and supplies.

On one side are the pressures exerted by U.S. business, labor and consumers. On the other - and usually at war with these domestic interests - is an administration promise to help the materials-producing countries of the Third World climb out of underdevelopment and poverty.

At issue in this copper-tin case is legislation sponsored by Rep. Morris K. Udall and Sen. Dennis DeConcini, both Arizona Democrats, that would have the government buy 225,000 tons of copper for the nation's strategic stockpile.

The objective is to reduce the 2 million-ton worldwide copper surplus that has driven prices downward since 1974, cutting into the profits of domestic producers and causing heavy unemployment in the five western copper-mining states.

In domestic terms, supporting the bill makes good sense for Carter. Western politicians and the copper industry have been demanding relief. The West has been a political troublespot for Corter because of administration stands on energy and environment issues.

Carter's support for the Arizonans' bill was followed quickly by DeConcini's decision to cast his needed Senate vote in favor of the first Panama Canal treaty.

But, however beneficial the president's action may be to his domestic political welfare. it has generated controversy abroad. That's because the plan calls for financing part of the copper purchase by selling what will amount to 50,000 tons of tin from the national stockpile.

The outcry has been particularly angunished from Bolivia, whose 5.6 million people have an annual per capita income of only $360 (second-lowest in Latin America) and whose in exports are virtually its sole source of foreign earnings.

The U.S. decision caused Banzer to send a letter to Carter expressing concern. Representatives of the state-controlled mining industry, led by the minister of miners, Ernesto Camacho Hurtado, issued an official communique calling the U.S. action "economic aggression" and an attempt to create "conflict among countries which produce and depend on raw materials" - themes that since have been echoed daily in the Bolivian press and radio.

Underscoring the Bolivian concern is the recent performance of the world tin market. In the weeks since it became known that the White House was moving toward support of the tin sale scheme, anticipation of the depressing effect on the market has cause the world price to fall from just under $6 a pound to around $4.75.

For Bolivia, which exports about 30,000 tons of tin a year, that could mean losses in the coming year of up to $60 million, even if the price doesn't drop futher. That's a sum almost double the U.S. aid contribution.

If the legislation is approved, Banzer, Camacho and other Bolivian officials have charged, the price almost certainly will fall much lower, drastically eroding the foreign-exchange earnings of a country that already pays 30 percent of its export earnings to service a foreign debt of close to $2 billion. That debt, which is almost equal to Bolivia's annual gross national product, is caused by its heavy dependence on outside loans and imports.

A financial squeeze of that mignitude, with the belt-tightening and unrest that would accompany it, couln't come at a worse time for Bolivia. Even U.S. diplomatic sources concede that an internal financial crisis could have very unsettling effects on a country preparing the transition back to civilian rule after a long period of civil war and dictatorship.

A financial squeeze of that mignitude, with the belt-tightening and unrest that would accompany it, couldn't come at a worse time for Bolivia. Even U.S. diplomatic sources concede that an internal financial crisis could have very unsettling effects on a country preparing the transition back to civillian rule after a long period of civil war and dictatorship.

Adding to Bolivia's bitterness is the fact that it sold the United States much of the 250,000 tons of tin in the national stockpile at special low prices during World War II and the Cold War era of the late 1940s and early 1950s.

The Bolivian mining industry says it made these sales as "an ally in the defense of democracy." It was understood, Camacho and industry spokesmen contend, that Washington would reserve most of the stockpile for strategic purposes in time of emergency, not use it to disrupt the world market through large-scale dumping.

Now the administration is abandoning that commitment in the face of domestic pressure, the Bolivians charge. In the process, they add, Carter also has turned away from his promises to help the Third World, in general, and Latin America, in particular, achieve stable prices and markets for raw materials exports.

These charges come on the heels of the anger provoked last fall when Carter bowed to demands from domestic sugar producers and raised tariffs steeply, causing big losses to Eatin producers.

That drew protests from the governments of such sugar-growing countries as the Dominican Republic, Peru, Guatemala, Panama and Brazil. Alejandro Orfila, secretary general of the Organization of American States, warned publicly of growing fears about being victimized by U.S. protectionism.

The response by administration officials to these charges and fears has not been especially strong. To the Bolivian complaints, for example, U.S. officials reply that, while the proposed legislation does pose risks for tin-producing countries, it also would create benefits for other parts of the Third World.

They point out that such copper producers as Chilie, Peru, Zambia and Zaire, whose exports have been hurt by the current world glut, would be help by the projected U.S. purchase.

In addition, administration sources note, world demand for tin currently is so high that, until the price drop triggered by the president's support of the copper bill, tin was selling at near record levels.

Even with the drop, they add, the price of tin now is roughly equivalent to the $4.75 that the International Tin Council, which includes producing and consuming countries, considers a fair price.

In short, they say, tin prices have been so high that the market can absorb some fluctuation and fall in prices. If the price goes up too much, the sources contend, the producing countries risk a drop in world consumption.

In addition, the administration believes it can cushion the effects of a tin sale by staggering it over a period of years, thus preventing the price from nosediving too far.

That argument hasn't been much comfort to the Bannergovernment. Its official position ( is that recent price levels show that the $4.75 outer limit set by the Tin Council was unrealistically low.

The Bolivians and some of their U.S. sympathizers even contend that the Udall-DeConcini bill would indirectly work against the Carter administration's human rights policy. That argument recently was stated publicly by the Washington Office on Latin America, and activist rights organization supported by liberal church groups.

WOLA, very critical of Bolivian rights violations in the past, said the country should be applauded and encouraged for recent strides in releasing political prisoners and restoring civil liberties. Instead, WOLA complained the Udall-DeConcini bill would penalize Bolivia while rewarding copper-producing Chile, which many rights advocates regard as the most repressive dictatorship in this hemisphere.

Privately, some administration sources concede that there is a lot of merit to the Bolivian complaints. just as there was to the protests of Latin America's sugar-producing countries last fall.

But, they add. When it comes to a choice between domestic political imperatives and relations with small, faraway countries, there's little doubt about which will prevail. As one source puts it: "It's the old question of how many Bolivians vote in U.S. congressional and presidental elections."