THERE is no question that the Soviet Union faces a food emergency requiring international help. And the perception is growing that help must be given quickly, not only for the obvious reason of averting hunger, even famine, but also to forestall such consequences as widespread violence, social dis- integration, and a tidal wave of refugees into Eastern Europe. But there is no consensus about who is to do what with whom for relief to be effective.Previous Russian famine and emergency operations are no road map in this totally new situation, but they are instructive. Today's problem seems more manageable and, for all its pitfalls, more positive in its context. A century ago, prolonged drought brought crop failure at a time when the peasantry had exhausted its reserves. Czar Alexander III simply denied the famine that followed, but when Count Leo Tolstoy appealed to the world, the government allowed private groups and the innocuous local councils to help. In so doing, it unwittingly stimulated initiatives that were forerunners of revolution. Nothing of that sort today; everyone admits to needing help. It can only come from outside. Thirty years later, in 1921, drought and famine struck again, this time on the heels of civil war. The Bolsheviks had won, but again no food reserves and again a broadcast appeal for help, this time by writer Maxim Gorky, among others. Only the United States could help, and a response quickly came from an American who had directed an immense, successful private effort to fight hunger in Europe during and after World War I. Herbert Clark Hoover, later to be an ill-starred president of the US, was an implacable foe of the new Communist regime but dismissed the objection that he would be helping it by feeding its population. Hoover had earlier insisted on sending food to areas controlled by the anti-Bolshevik, white Russian forces. Now, with the reds victorious, he rejected suggestions that his organization, the American Relief Administration (ARA), undermined the Bolshevik regime. He brooked no interference. He demanded freedom of all American prisoners in Russia (and a surprising number of more than 100 was at once released). Americans were to have full liberty to administer the relief, to travel without hindrance, and to organize local committees. Distribution was to be nonpolitical. Storage, transportation, and offices would be free. And Hoover made the Communist state contribute some $18 million of the czarist gold in its vaults. By the spring of 1922, with a staff of 200 American volunteers, the ARA was giving food to 18 million people. Of the estimated 15 to 20 million adults and children in danger of starvation at the outset, fewer than 1 million lives were lost. DURING World War II, the Soviet Union received large quantities of mainly military supplies under the American lend-lease program. That ended with the Japanese surrender. But food and relief continued to come from a new international organization, UNRRA, the United Nations Relief and Rehabilitation Administration. Formed at the end of 1943 by 44 nations to prevent starvation and aid recovery in liberated territory, UNRRA was as long on performance as it was short on staff. In 1946, it was the world's l argest single exporter. When it started closing down in March 1947, it had delivered more than 22 million metric tons from countries all over the globe. As the largest contributor, the US named UNRRA's director general, first Herbert H. Lehman, then, in 1946, the feisty Fiorello LaGuardia. By that time, Stalin had started the cold war and was soft-pedaling the receipt of Western aid. LaGuardia, visiting Moscow, heard from foreign reporters that they were not allowed to follow the distribution. He had an appointment with Stalin that night. Within 24 hours the reporters were on a trip to Byelorussia and the Ukraine. We saw acres of lend-lease equipment rus ting on the Odessa docks. However, the official Soviet food supply line worked - with the party, needless to say, in first place. The 1991 Soviet aid program will face serious problems of disorganization and incompetence, with touches of sabotage and the inertia of Communist habit. Transport and storage may not function but the black market will. The disjunctions and nationalism of the rising republics pose new difficulties. But some of the old lessons apply. The donors should closely coordinate their efforts under a single, strong management, not fall over each other in separate ventures. Operational authority must be clearly defi ned. Above all, no politics. A humanitarian act must be precisely that if it is not to harm all the parties involved.