In a half year's time, the rich nations of the world, with the United States leading the way, have outrun Ethiopia's famine.

Triggered last fall by televised images of starvation, a crash mobilization of food aid is now dumping mountains of grain at Ethiopia's ports. For the 7.9 million people threatened by famine, there is now within this country a two-month cushion of food.

In outrunning the famine, however, the world's donor nations and the United States in particular have moved into a phase of disaster relief that is far more logistically complicated and politically confused than simply putting food before starving people.

On the logistical level, a transportation bottleneck has developed since the first of the year. Sixty percent of the 332,000 tons of food delivered here since January has not been distributed, according to a report given donors this week. The report said Ethiopia has less than half the trucks required to deliver the more than 100,000 tons of food that are arriving each month at Ethiopia's ports.

On the political level, strings tied to aid provided by the United States, which bankrolls one-third of the relief effort in this country, are preventing its use to help buy trucks to unclog a transportation problem hindering delivery of U.S. food.

These restrictions also prevent relief agencies here from using U.S. aid for any project deemed to "develop" Ethiopia, a country whose Marxist military government continues to share unfriendly relations with the United States.

Strings on U.S. aid, which were seen as legalistic curiosities when America's outpouring of food and money began last fall, have become infuriating facts of life for the relief agencies here that are the U.S. government's designated conduits of aid to the Ethiopian people.

In interviews here this week, officials of five of the largest private relief organizations in Ethiopia -- Catholic Relief Services, Lutheran World Federation, CARE, Oxfam and Save the Children -- said that restrictions on the use of U.S. food and money are beginning to undermine efforts to help Ethiopia recover from the famine.

Their frustration was echoed in interviews with Kurt Jansson, U.N. assistant secretary general for emergency operations in Ethiopia, and with Maurice Strong, the top U.N. official for famine relief in Africa.

In particular, these officials condemn restrictions that prevent relief agencies from using U.S. food as pay for Ethiopian famine victims who are rehabilitating the drought-seared central highlands, rebuilding their farms, digging irrigation ditches or building roads.

"We can only give American food to people who are sitting on their ass . . . . This is schizophrenic aid. You keep people alive only to starve," said Niels Nikolasen, chief representative for Luthern World Federation, one of the major distributors here of U.S. aid. "We appreciate very much the American food, but in the long-term, what good does it do?

"For what has gone on in Ethiopia up until now, the American people can be very proud of their aid. But three months from now, as the need to rehabilitate this country becomes increasingly urgent, I don't think they could be proud anymore."

Alex Rondos, a spokesman in Ethiopia for Catholic Relief Services, the giant American operation that moves more U.S. food than any other agency, said that restrictions on the use of American food are crimping its efforts to keep peasants on their farms and out of relief camps.

"There is a point in any relief effort -- and we have reached it -- when there is a degree of stability amid the misery. You are conscience-bound to move on to rehabilitation," Rondos said. "Americans cannot go around Ethiopia simply salving their guilt with handouts. There is more to relief than just that.

"If we could do any type of food for work, we could prevent further and likely displacement of more people. That is the fundamental point of being here, isn't it? The whole object of our work is to prevent these rather ghastly camps from growing."

The head of Great Britain's Oxfam operation here, Hugh Goyder, said that unless restrictions on the use of U.S. aid are modified it may end up doing more harm than good.

"So many people will have become dependent on handouts and the infrastructure of the country will not have been improved," Goyder said.

"It is absolutely crazy. The U.S. delusion is that if you throw a lot of food at this problem it will go away. It won't. The drought will come again. And I believe that if nothing is done in agriculture development, health and water, it could be worse in Ethiopia in five years' time," he said.

American food aid to Ethiopia is bound by strings attatched to two amendments to the U.S. Foreign Assistance Act. The amendments prevent the government from giving anything other than "humanitarian" aid to countries that have not paid their debts to America.

The first amendment, the so-called Hickenlooper Amendment, which is widely known and despised by relief workers across Ethiopia, prevents development aid to countries, such as Ethiopia, which have nationalized the property of U.S. citizens and have not taken "appropriate steps" to pay for it. The law is named after the late senator Bourke Hickenlooper, a conservative Republican from Iowa, and was passed in 1962 in response to nationalization of property in Brazil.

While the Ethiopian government has begun compensating Americans for property seized after its 1974 revolution, there still are about $30 million in outstanding debts.

State department lawyers have ruled recently that "appropriate steps" can be "whatever President Reagan decides. Hickenlooper could be waived by the president this afternoon," said a Washington-based official for the U.S. Agency for Internatonal Development.

The second amendment restricting U.S. aid, named after former Republican senator Edward Brooke of Massachusetts, prevents development aid to countries that have not paid off loans to the U.S. government. When Ethiopia turned away from the United States in 1977 and turned toward the Soviet Union, it failed to repay U.S. loans for military hardware. Ironically, due to the break in relations, some of that hardware was never delivered here.

While the Brooke Amendment is all but unknown to relief officials in Ethiopia, a State Department official in Washington said recently that it would be much more difficult to waive than the Hickenlooper Amendment.

"When Hickenlooper is resolved, there will be Brooke. The language of Brooke is such that Reagan can waive it only in the event of a national security threat to the United States," the State Department official said.

"We have had meetings around this building the State Department about Hickenlooper and Brooke," the official added, "but there is no feeling around Washington that it is a crisis."

As 415,817 tons of American aid pour into Ethiopia this year, AID officials here -- with regular guidance by cable from Washington -- are forced by Hickenlooper and Brooke to make hundreds of judgments about what uses of this food and money is relief and allowed or developmental and forbidden.

Save the Children approached AID officials last fall with a request for money to purchase seed to plant in northern Shewa Province. Such a use of U.S. money was ruled "out of the question" by AID, according to Gerald Salole, director of the U.S. chapter of the Save the Children. Lacking seed, he said the area will miss the main sorghum planting season.

Working with Oxfam, AID officials agreed early this year to help fund a water program in drought-ravaged Wollo Province. According to Oxfam's Goyder," they paid for 12 holes in the ground, but wouldn't pay for the equipment to get the water out."

"Sometimes the U.S. can be unbelievably generous, and sometimes I don't know why they don't come forward," said Roman Roos, the U.N. specialist here on transportation. He made an appeal Tuesday to donors for $50 million worth of trucks and spare parts. "There is no option, if they want to feed the hungry with their food, but to provide the transportation."

No one with AID in Ethiopia will speak on the record about the restrictions, other than to say they are enforcing the law. But many African development specialists in the agency say they are frustrated with the law. They encourage private relief agencies in Washington to lobby both the White House and Congress for change.

Three senior State Department specialists on Africa, who recently predicted no movement on the Hickenlooper or Brooke amendments, said in interviews in Washington that development work with Ethiopia is nearly impossible because of acrimony and philosophical differences between the U.S. and Ethiopian governments.

"The U.S. is in a terrible position in Ethiopia," said an AID official in Washington recently. "It cannot do any of the policy stuff it would like, such as pushing the Ethiopian government to increase incentives for farmers through higher prices. At the same time, without setting out to do so, it has become the biggest donor."

Relief officials here argue that the United States need not talk policy with Ethiopia to put its food -- as distributed by private agencies -- to the best use.

"It is still not too late. We believe you can aid Ethiopia without helping its Marxist system or helping to fight its damnable wars," Goyder said. "You target it to particular projects, to seed production, to health, to rural roads."

The particular gripe of nearly every relief agency in Ethiopia is the prohibition against using U.S. food in food-for-work programs.

Lutheran World Federation, for example, has begun food for work in Eritrea aimed at digging out silted-over dams so nearby peasants will have water for irrigation and drinking. At one dam near a town called Keren, 3,800 people have been put to work carrying dirt in bags on their backs. For every meter of dirt moved, a family earns 17.6 pounds of Swedish or Canadian grain. It cannot be U.S. grain.

The Lutherans and the Catholics, who together feed 1.6 million Ethiopians daily with U.S. food, would prefer that at least 1 million of these people worked for their meals. "Every day we and the Catholics pray that the U.S. will allow food for work," said Nikolasen.

As months go by and more and more U.S. aid floods into Ethiopia, relief officials here -- many of them Americans -- say they are becoming increasingly frustrated and bitter.

At Lutheran World Federation, Nikolasen, a Dane, says his frustration with U.S. aid restrictions is contained only because "up here in Ethiopia we work. We cannot give . . . attention to screaming."