BRUSSELS -- The end of the Cold War takes U.S. and European aid to the Third World off automatic pilot. A major reappraisal of why and where aid money goes in Africa, Asia and Latin America is now unavoidable.

It is time to make genuine political reform a condition for receiving economic and military assistance from the nations and institutions of the developed world.

Political ''conditionality,'' in multilateral-aid-trade jargon, has been imposed for the first time by the United States and 23 other aid-giving nations on the six East European countries emerging from Soviet rule. Romania flunked the democratic test and gets no aid from the Group of 24. That is a trend that one hopes will spread.

Why should the dictators of Zaire or Kenya be able to treat dissidents as brutally as Romania's barely de-Stalinized bosses and still get $50 million a year each in support from U.S. taxpayers? In what ways are the regimes of Mobutu Sese Seko and Daniel arap Moi more deserving than that of Ion Iliescu? Especially when in Zaire and Kenya it is widely believed they are siphoning off government funds for their own profit?

These are questions the aid and military support bureaucracies of Washington, London and Paris will have to confront directly now that they can no longer hide behind the alleged strategic Soviet threat to former colonies. The famous ''at least he is our s.o.b.'' rationale will soon cut little ice. There will be no one else to be an s.o.b. for.

This leads some to argue that foreign aid is obsolete as a concept. The collapse of Soviet global ambition makes it unnecessary for the United States to try to buy friendship and stability in countries that could once threaten to go over to the Soviet camp. Without the Soviet threat to thwart, the United States has no interest to protect in Liberia, Egypt, the Philippines or Peru, it is argued.

The collapse of Soviet global ambition is eloquent testimony to the fact that the Soviets turned out to be a greater threat to themselves than to American interests in the Third World. Soviet ''victories'' in Angola, Cuba, Yemen, Vietnam and elsewhere created an overextended, expensive Soviet presence abroad, which led to economic disaster at home. The United States should have been shoving as many Angolas and Yemens at Moscow as possible.

While secretaries of state never seemed to grasp this nuance of the superpower struggle, many U.S. diplomats and military attaches serving in the Third World did. But they also knew that the easiest way to get funding for their nice little country and their own embassies was to conjure up a Soviet menace on the doorstep. They joined the Soviets in a Great Pretense, which meant good places at the trough for Mobutu and Co.

Now the United States and the Soviet Union are agreeing to wind down their proxy wars in the Third World. Secretary of State James A. Baker III and Soviet Foreign Minister Eduard Shevardnadze reached tentative agreement in Paris two weeks ago on a power-sharing settlement in Afghanistan, Soviet sources said after that meeting. U.S. officials have been more pessimistic.

The Soviets have also suggested to recent American visitors that their large economic and military support for Fidel Castro is in its final year. The ending of the strategic Moscow-Havana link will resolve the last major point of conflict between the superpowers in the Third World.

But to eliminate U.S. foreign aid altogether as a result would be to throw out the baby with the bath water. The affluent North has clearly identifiable interests in the poor South that are independent of superpower rivalry. It is in fact now easier to see what those interests are and to respond to them without self-deception.

France, Italy and Spain, for example, are beginning to concentrate aid efforts on the North African states of Tunisia, Algeria and Morocco. These states are to Mediterranean Europe what Mexico and Central America are to the United States -- the source of a huge wave of unwanted migration if economic and political conditions worsen dramatically there.

French politicians view the Maghreb as ''a ticking time bomb,'' and the government has opened urgent discussions with Algeria on a big new package of financial credits. There is an awareness here that such programs will be effective in cutting off emigration only if they lead to improved economic and political conditions in Algeria.

Ultimately that means achieving democracy. French officials are using the East European example to prod African autocrats to liberalize their systems to get future help.

Unless it intends to practice reverse racism, the United States can demand no less of Mobutu and Moi than it demands of the Romanians and Poles. And the United States can no longer postpone ensuring that its largest single aid recipient, Israel, grants authentic democratic freedoms to the Palestinians of the West Bank and Gaza Strip.

Only an aid program based on spreading democracy in fact, not just in rhetoric, can survive in a changing world.