IN THE END, the Ugandan people became again the arbiters of their own fate, receiving the Tanzanian force that had come to depose Idi Amin as liberators. Mr. Amin, a mass-murderer, could find virtually no countrymen willing to help him defend his power. He had been reduced to relying on the legion sent him by a fellow fanatic, Libya's Muammar Qaddafi, and it disintegrated, too. That the burly, bellicose Amin fell ultimately at the hands of the slight Tanzanian leader Julius Nyerere, whom he had ridiculed as a a pushover, lends the quality of an African parable to an important political event.

Unfortunately, Mr. Amin's downfall has produced a cry for revenge and the sort of abandon that often comes when a dictator departs and leaves behind neither the habit of order nor the structure of law. The first victims are among the Muslim minority, which ex-president Amin, himself born a Muslim, cultivated after he alienated Uganda's dominant Christian tribes. Uganda needs no sermons about the irony of fresh tribal and religious bloodshed. It needs a strong local authority determined to protect all citizens. For the moment, the Tanzanian army must shoulder this responsibility. The provisional government of Yusufu Lule must take it over as soon as it can. Mr. Lule, a 67-year-old former academic brought out of retirement as a compromise choice of the defferent factions opposing Mr. Amin, faces a formidale reconstruction task. He promises prompt elections. He will need to deliver that, and much more. The United States and Uganda's other friends can help.

Already some observers, not necessarily cynics, are predicting that, with the downfall of the despotic Amin, Uganda will lose its claim on international attention and will become, as one person put it, "just another tiresome African country going nowhere." In a sense, a return to normality might be a welcome step up for a country that has gone through the wringer as Uganda has it the eight Amin years. Yet Ugandans clearly deserve something better. In particular, they have a right to expect an easing of some of the draining rivalries Uganda has conducted with some neighboring states-Kenya comes first to mind. Idi Amin's political passing permits a frest start for the whole of East Africa. All of the countries there have dismaying problems, and all of those problems would be less daunting if the countries faced them together.