REVOLUTIONS can be exhilarating. But in the heat of the hour new leaders and groups can overstep their ability to govern and conduct business legitimately and fairly. Without a mature rule of law and democratic political culture, disagreements are more likely to lead to chaos and violence.The Soviet Union is rapidly deconstructing. But for now the various Soviet republics - with the clear exception of the Baltic states - need some form of union, albeit a union without party functionaries and the poisonous influence of the KGB octopus. All 15 current Soviet republics have either declared independence or an intention to secede from the current union held tenuously together by Gorbachev and a team of Russian Republic liberals. Some republics are more dependent on Soviet Russia. Others, such as the Ukraine, are less dependent. Such conditions will certainly determine the terms and timing of genuine independence. Yet for now a union that will mediate military matters and economic ties among republics - particularly between Russia and others - is needed. Such a treaty ensures a balance of power and rule of law during a time of unprecedented change. Gorbachev and Boris Yeltsin must recognize this. The danger is the old European problem of unchecked nationalism and ethnic strife - action and terrible reaction. In this sense the Russian right-wing Col. Viktor Alksnis is credible, warning of strife like that in Yugoslavia today between minority Serbs and Croats in Croatia. The scenario of strife between ethnic Russians and local ethnics in the Central Asian republics of Kirghizia, Tadzhikistan, Turkmenia, and Uzbekistan is not unlikely. Hatred simmers between the two groups - fueled by their widely divergent cultures. Russians killed by nationalists in Uzbekistan would trigger an equal rise of feeling in Russia. Already, borders are under dispute, with Russians possibly claiming territory for their own nationals. Yeltsin's comments to this effect have not been helpful. Republics must loudly affirm the promotion of minority rights. The West must make clear to all republics the need to do so - with aid withdrawn for violations. The Baltics, recognized by 20 states including Britain, Germany, and France, are a separate case - states illegally annexed in 1940, which weren't as tied to Czarist Russia as other republics. Groupings and associations have helped check power blocs in Europe. During a delicate transition period, a new union group is needed in the Soviet region.