PARIS, NOV. 21 -- In the old days, Mikhail Gorbachev could at least be assured of a respite from his domestic problems when he traveled abroad. No more, it seems. At the moment of his greatest international triumph -- the ceremonial end to the Cold War -- the Soviet president was stalked by fractious Balts, Ukrainians and Armenians, all questioning his right to speak on their behalf.

The tragicomic spectacle of rival Soviet delegations showing up in Paris for the 34-nation European summit raised the serious question of how much political authority Gorbachev now wields as the world's largest country breaks down into component parts. It also underlined the dramatic differences in the way in which this year's Nobel Peace Prize laureate is perceived at home and abroad.

Abroad, Gorbachev is still feted as the visionary statesman who transformed U.S.-Soviet relations, liberated Eastern Europe, allowed Germany to be reunited and dismantled totalitarianism in the Soviet Union. The Soviet leader's international status was reflected in the size of his motorcade -- three Zil limousines that give new meaning to the word "stretch," dozens of motorcycle outriders and a small army of exotically armed bodyguards in black jumpsuits.

At home, however, Gorbachev is seen as an increasingly ineffectual leader in danger of being overtaken by events that he himself helped set in motion. A familiar pattern has now begun to emerge. Every time there is a crisis, the Soviet leader gets the legislature to grant him increased executive powers. But the powers turn out to be insufficient to break the cycle of economic decline and centrifugal nationalist trends. The crises follow each other in increasingly rapid succession -- and each is more serious than the last.

"For the West, the Soviet Union means Gorbachev, but this is not very far-sighted," said Galastyan Ambartsum, a representative of Soviet Armenia's recently elected nationalist government who tried without success to gate-crash the summit. "Western governments think it is in their interests to support Gorbachev because he gave them arms agreements, freed Eastern Europe. But they don't understand that world peace is impossible if there is domestic strife in the Soviet Union. If Gorbachev goes against the republics, conflict is unavoidable."

For the nationalists, who now hold power in five of the Soviet Union's 15 republics and are an increasingly influential force in several others, the only reasonable way of holding the territories of the former Russian empire together is first to allow them to split apart. Economic self-interest, they argue, will eventually force the new sovereign states to cooperate with each other and form new supranational bodies. But this has to be done from the bottom up, rather than from the top down.

For the moment, Western leaders seem more impressed by Gorbachev's counter-argument -- that a much greater threat to world peace would come from the breakup of a multinational state that possesses more than 10,000 nuclear weapons. Western support for the restoration of the prewar independence of the three Baltic states has been largely symbolic. After a complaint from the Soviet delegation, the French organizers of the conference swiftly withdrew the "guest" credentials that they had issued to the Baltic foreign ministers.

In trouble at home, Gorbachev has sought to draw on the reserve of goodwill he has accumulated with Western governments to gain assistance for the Soviet economy. This week, he collected further promises of credits worth $1 billion from the European Community in addition to substantial food aid from Canada. Gorbachev also went to some lengths to brief Western leaders on his domestic problems, evidently hoping that they will show understanding and restraint if he needs to take tough action to deal with social disorder over the coming months.

On the international stage, Gorbachev's political authority has derived from the stunning changes that have taken place in East-West relations since he came to power in 1985. At first, he enjoyed a similar kind of legitimacy within the Soviet Union, as the initiator of dramatic reforms that reversed seven decades of dictatorial rule. But this legitimacy is being undermined as his perestroika reform movement runs into difficulty.

Ironically, as a result of last year's changes in Eastern Europe, which he partly inspired, the Soviet president is now the only major European leader who has never won a real election. The Communist Party nominated him for one of a bloc of 750 uncontested seats in the 2,250-seat Soviet Congress of People's Deputies, which then proceeded to elect him president against only token opposition.

A year ago, Gorbachev would probably have had little difficulty getting himself elected president in a nationwide ballot. He declined to hold such an election on the grounds that it would prove unnecessarily divisive and distractive at a time when the country had more important things to worry about. With hindsight, however, the failure to hold a direct presidential election has deprived Gorbachev of a clearly recognized popular mandate to implement the painful transition to a market economy.

Addressing the legislature last week, Gorbachev complained that many of his orders were being deliberately ignored, either by the republics or by low-level bureaucrats. But while it is undoubtedly true that the fracturing of political authority in the Soviet Union has complicated the president's task, the real reason for the present impasse seems to lie deeper. The fact is that Gorbachev himself has shied away from implementing some of his own policies -- such as freeing prices and ordering vigilante groups to surrender their arms -- because he fears a popular explosion.

One of Gorbachev's senior political advisers, Georgi Shaknazarov, was probably closer to the mark when he compared the Soviet Union's present plight to the economic paralysis in Poland before the Solidarity government came to power last year. "The Polish example shows that a government that enjoys public trust can undertake very far-reaching reforms. If it does not have public trust, then this is virtually impossible," he said.

The streamlining of executive authority announced by the Kremlin last week should go some way to removing the bureaucratic obstacles that Gorbachev has complained about. The beefed-up Federation Council, which includes the leaders of the 15 republics, will provide an institutional framework for reconciling their disparate interests. But it remains to be seen whether this will resolve the Soviet Union's underlying problems.

Gorbachev's talent for coming up with fresh political gimmicks -- rather than fundamental economic reform -- is reflected in a joke now making the rounds of Moscow. Worried that the Kremlin is falling down, officials ask Gorbachev what should be done. "Draw a circle on the wall," he replies. The instruction is carried out, but the fortress continues to collapse. "Draw a triangle around the circle," Gorbachev orders. Still no improvement, but the president is unperturbed: "Okay, let's draw a square around the triangle."

The officials finally come to Gorbachev with bad news: The Kremlin has completely collapsed. Gorbachev is amazed and shocked: "What a pity. I had so many more ideas that we still haven't tried."