Can’t Live With ‘Em, Can’t Live Without ‘Em : The fading ideal of unity among the ex-Soviet states has been revived somewhat by an awareness of how hard it is to manage without each other.

When the Soviet empire broke apart a year ago, one chunk that survived was its indivisible railway network--92,000 miles of track sprawled across two continents.

But where did all the railroad cars go?

Trains that left Russia to deliver cargo to the newly independent republics started coming back minus some cars. Or with cars noticeably older and rustier. Quickly forming their own rail companies, the breakaway republics started ripping off the newest freight cars, at Russia’s expense.

Then the Commonwealth of Independent States lumbered into action. At Russia’s request, it convened the new railroad executives and thought up a solution: They simply divided the thousands of freight cars among them and gave each a license number so there could be no further disputes.

After a year as the Soviet Union’s successor alliance, the Commonwealth works more like a court litigating a dead patriarch’s estate than a common market or a Eurasian NATO, or even a well-run railroad. Like heirs in a large, unhappy family, its 11 members spend their time together quarreling over property, money supply and trade prices.

Although doomed to cooperate for the sake of survival, the former Soviet republics are more focused on internal problems under widely varying programs of post-Communist reform. Some are crippled by ethnic and clan conflict. Two are at war with each other.

Even as an agent of disunion, the Commonwealth has no charter. It does have a military commander, but he commands no troops. Its member states’ presidents have met eight times and signed 240 “agreements.” But they cannot agree on enforcement.

“The Commonwealth is the world’s biggest fig leaf,” said Paul A. Goble, an American expert on Soviet nationalities at the Carnegie Endowment for International Peace in Washington. “It was created to cover the loss of an empire. Like all fig leaves, it will eventually wither and fall off.”

The Commonwealth was founded Dec. 8, 1991, by Russia, Ukraine and Belarus to thwart Soviet President Mikhail S. Gorbachev’s plan for a looser Soviet Union. By year’s end, the empire was gone and eight other republics had joined the new alliance in the hope that it would promote their common interests as independent nations.

From the start, the Commonwealth divided into two camps: Russia, Belarus, Armenia and Central Asian republics that want to stay closely tied to Russia, and the others, led by Ukraine, that fear being dominated by Moscow almost as much as being cut off completely.

Differences between the two blocs have impeded efforts to set up a Commonwealth military force and a council to coordinate currency and credit policies of nations whose economies are more closely intertwined than those of Western Europe.

To placate the West, a strategic Commonwealth command was set up last February to oversee nuclear weapons in Russia, Ukraine, Belarus and Kazakhstan. But the hopes of the smaller and poorer republics for a joint conventional force vanished when Ukraine and Moldova set up their own.

In response, Russia created its own army and claimed jurisdiction over former Soviet troops on the territory of Commonwealth member states.

At the same time, Russia supported a Commonwealth decision last July to assemble a joint peacekeeping force for troubled areas. But the idea was blocked by nationalist opposition around the Commonwealth. As a result, the alliance is powerless to halt escalations of ethnic warfare between Armenia and Azerbaijan, between the Moldovan government and Russian-speaking separatists or between ex-Communists and Islamic guerrillas in Tajikistan.

A dispute earlier this year between Russia and Ukraine over ownership of the former Soviet navy’s Black Sea Fleet threatened to wreck the Commonwealth altogether. Those fears eased after Presidents Boris N. Yeltsin of Russia and Leonid M. Kravchuk of Ukraine agreed how to divide the fleet.

Meanwhile, the flickering Commonwealth ideal was revived somewhat by a growing awareness among its members, after months of fruitless efforts to prosper through trade with the West or with Asia, of how hard it is to manage without each other.

In a frank admission of that reality, Ukrainian Prime Minister Leonid Kuchma told his nation’s legislature last month that “Ukraine has waged, and lost, an economic war” to break ties with Russia. “The road to self-isolation led nowhere,” he added.

The breakdown of the Soviet command economy has thrown all 15 former republics into recession and confusion. The highly integrated Soviet system distributed materials from parts-making factories in some republics to assembly plants in others.

Russia has tried to ease the blow to its neighbors by keeping its export prices for oil and gas well below world levels for trade in the Commonwealth in a bid to buy stability on its Central Asia borders.

Lately, however, Russia has been playing tougher. Lithuania, which shunned the Commonwealth, found its Russian gas supplies cut off last August in a dispute over pricing. In part because of the resulting hardships, Communists made a stunning comeback in Lithuanian elections two months later.

The engineer of Russia’s get-tough policy, former Energy Minister Viktor S. Chernomyrdin, became prime minister last month in a government shake-up. His rise signals a more nationalistic Russian line within the Commonwealth.

“Russia is like an icebreaker. If you don’t steer in its wake, ice floes will crush you,” Kyrgyzstan President Askar Akayev recently told the Moscow newspaper Komsomolskaya Pravda.

Because they are poorer and more vulnerable, Akayev’s country and the four others in Central Asia have taken the lead in demanding a more centralized Commonwealth. Meeting Monday, their presidents called for a powerful economic council to which each Commonwealth nation would cede some authority in regulating the supply of Soviet rubles that are still the common currency.

But Moscow has rejected any shared decision-making about the ruble. It has told neighboring republics to live with its monetary policy or drop out of the ruble zone and pay hard currency for Russian exports. So far, Ukraine, Moldova, Turkmenistan and Azerbaijan have moved to set up their own currencies.

“The Commonwealth is not working as a military or economic alliance,” said Andrei Kortunov at the USA-Canada Institute in Moscow. “There is only one function left for it--that of a regional United Nations, a forum where the presidents can go and attract attention, score a few points. If you want to solve real problems, you meet bilaterally.”

Pieces of the Soviet Puzzle

Of the 15 republics that made up the Soviet Union, eight became full-fledged members of the Commonwealth of Independent States. Two others, Moldova and Azerbaijan, are awaiting approval from their parliaments. Azerbaijan has retreated to observer status. Georgia has never been a Commonwealth member but has sent observers to Commonwealth summits and even signed one Commonwealth agreement. Lithuania, Latvia and Estonia have shunned the Commonwealth.

The official members: Russia, Belarus, Armenia, Turkmenistan, Uzbekistan, Tajikistan, Kyrgyzstan, Kazakstan and Ukraine

Other Ways They’ve Teamed Up

Ruble zone (republics that use the old Soviet ruble as their currency and have submitted to monetary and Russian credit controls): Russia, Belarus, Armenia, Kazakhstan, Tajikistan, Uzbekistan, Kyrgyzstan and Georgia

Commonwealth security pact (each pledges to to come to the other’s aid in case of attack): Russia, Armenia, Kazakhstan, Uzbekistan, Turkmenistan and Tajikistan