Worried Europe Will Seek Reassurance : Diplomacy: A special envoy will remind Moscow, Kiev and Minsk of the need to comply with international obligations.

European Community leaders expressed deep concern Monday about the dissolution of the Soviet Union and announced that they will send a special ambassador to the capitals of Russia, Ukraine and Belarus.

Dutch Foreign Minister Hans van Den Broeck, whose nation is hosting the summit conference here, declared that the EC envoy will remind the republics of the need for “compliance with international obligations entered into by the Soviet Union, notably in the field of arms control.”

Besides their worries about who now will assume responsibility for the giant Soviet debt, the Western European leaders are particularly edgy about the presence of nuclear weapons in Ukraine and Belarus (formerly Byelorussia), fearing the arms might pass to uncertain, local control.

The EC heads of government discussed the volatile situation in the proposed Slavic commonwealth at dinner one night after republic leaders announced what they called the effective junking of the Soviet Union.

“It would be tragic if the Soviet Union ended up like Yugoslavia,” remarked Danish Prime Minister Poul Schlueter, reflecting the EC’s anxiety that the Soviet disintegration might lead to the kind of bitter ethnic strife that already has claimed thousands of lives in the Balkans.

But, while concern about the fate of the Soviet Union was widespread here, it was unclear whether the EC leaders would make a specific joint statement on the issue. In particular, the Germans--who are eager to cement Western Europe’s economic union--do not wish to complicate those already difficult negotiations.

“Five days ago, the question was asked whether the Ukraine and Russia would go to civil war,” said a high-level German official. “What’s going on in Minsk is to avoid this.”

The same official said the German government is seeking clarification about the new Slavic commonwealth and its implications for Western Europe.

“We have had contact with Foreign Minister (Eduard A.) Shevardnadze and will speak to (Russian President) Boris Yeltsin on Tuesday. We’re in contact with the Americans looking to see how to deal with the situation,” he said.

“It’s a development that hasn’t surprised us,” added a senior German Foreign Ministry official, “but one which we are following with anticipation and interest.”

British Prime Minister John Major said Monday of the announcement of a Slavic commonwealth: “We are concerned about what has happened there. We have been in touch with the United States overnight and will be meeting (French) President (Francois) Mitterrand on Monday.”

Major said that Britain, the United States and France--the only Western nuclear powers--worry about control of Soviet atomic weapons. His concern was amplified by British Foreign Secretary Douglas Hurd, who later declared: “I think the Soviet Union has been coming apart for a long time, and yesterday’s announcement may have been the final blow. But I think it will be some time before we see the new pattern at all clearly.

“We can’t work out in what way the peoples of the Soviet Union should organize themselves,” Hurd said. “What we can say to them--what we are saying to them--is: ‘We have certain undertakings from your predecessors, from (Soviet) President (Mikhail S.) Gorbachev and the Soviet Union, on nuclear weapons, on the size of your conventional forces, on the debts of the Soviet Union. All those are very important for the future, and they can’t just be shrugged off.’ ”

In expressing concerns of other EC leaders here, Hurd added: “In order to have a safe world, we do need certain undertakings as to how the people holding those nuclear weapons behave.”

Hurd said the British “have made it clear” to Ukraine and other republics that “we wish them well, we have no desire to interfere with the way in which they work together or the way in which they assert their independence” provided they fulfill their obligations to assure other nations of their peaceful intent, control of nuclear weapons and willingness to assume their share of debts incurred by the Soviet Union. Russia, Ukraine and Belarus, he added, are “respected because all three of them are of very great importance to the West.”

Ulrich Weisenberg of the German Economic Institute in Berlin took a positive view of the announced Slavic commonwealth, commenting: “It’s a peaceful solution and a peaceful way for the republics to go their own way. That is positive and something to welcome. It’s a model to prevent the proliferation of nuclear weapons.”

He noted that “Ukraine has said it doesn’t want to keep its nukes but doesn’t want others to have them. . . . A (Slavic) commonwealth could be a vehicle to prevent tension with Russia on this issue.” But he warned: “There is one uncalculable factor in this--the army. An army without political control is unpredictable.”

In their Sunday agreement, the three Slavic republics said they will “strive for the liquidation of nuclear weapons, complete disarmament under international control.” U.S. military sources estimate that the Soviet Union has about 27,000 nuclear weapons--about 21,600 of them in Russia and the rest in Ukraine, Belarus and the Central Asian republic of Kazakhstan.