Much as its great rival the United States, the Soviet Union in the 1980s confronts a decade of unprecedented economic strain with no guarantee its leadership has either the will or the competence to master the challenge.

Three complex factors intersect, foreboding trouble in this decade as never before in Soviet history -- energy, manpower and labor productivity.

Moscow faces the unusual prospect of sharp limitations in the expansion of these basic ingredients of economic success. The impact could be significant in the Kremlin's relationship with its restless East European allies, its great-power ambitions and its political and trade relations with the capitalist nations.

In addition, there is the distinct likelihood that unless remedies can be found, Soviet living standards, already the lowest among the world's major industrial powers, will fall further behind despite endless leadership promises of a better material life after decades of sacrifice.

These difficulties approach at a time when the ruling Communist Party will be preoccupied with internal political complications connected with eventual transition from the leadership of Leonid Brezhnev to his successor.

They have intensified Western concerns about the global dangers posed by Soviet economic troubles. The problems also have increased the debate in the West about the possible opportunities gained by using the sale of capitalist technology to modify Soviet behavior. It is believed such technology could reverse the steady sag of Soviet industrial expansion.

Soviet military intervention in Afghanistan in December sharpened these debates, while dealing a blow to Western moderates who hoped the Kremlin's 1970s detente policy of seeking improved Western trade had implicitly ruled out such threatening foreign adventures.

It is known from Soviet sources as well that inner circles of the party have intensified calculations about whether the U.S. grain and technology embargo has shown the Soviet Union dangerously vulnerable to Western pressures.

At the same time, the pause in Soviet-American arms control negotiations resulting from the Afghan crisis has raised for Moscow the disturbing possibility that it may be forced to devote even more resources from its much smaller national economy into its large defense industries in a new strategic weapons race with the United States.

As usual, the Soviets betrayed none of these worries in the recent Vienna talks between Foreign Minister Andrei Gromyko and Secretary of State Edmund Muskie, or in the meeting in Warsaw between Brezhnev and French President Valery Giscard d'Estaing. Moscow is unyielding in its Afghan intervention despite the threat of long-term harm to its attempts to import from the West the badly needed technology it cannot produce.

The stage for economic troubles in the 1980s was set in the 1970s, when the rate of Soviet economic growth steadily slowed under the burdens of low productivity, squandered industrial capitalization, bureaucratic inflexibility and several harvest disasters.

Yearly economic expansion in the last decade hovered around 3 percent, well short of both official goals and the rates of the 1960s. The powerful state planning committee, Gosplan, and the Communist Party Central Committee are deliberating in secret over new targets to be set in the next five-year plan, covering 1981-85. Few clues are available publicly here over the nature of those debates, but the most intense area of concern, as in the West, is known to be energy.

Soviet petroleum production was the great development feat of the 1970s. By pouring massive resources into vast oil and gas fields centered at Tyumen in western Siberia, about 1,800 miles east of Moscow, the Soviets vaulted to first place among world oil producers, pumping 11.7 million barrels daily last year. Half of its oil and a third of its natural gas come from Siberia, Maxim Gorky's "land of death and chains."

It would be difficult to underestimate the political and economic wellbeing this energy has brought Moscow. Daily, 3 million barrels of oil are exported to capitalist Europe and the socialist Comecon trading group of the Warsaw Pact. Soviet oil buffers both Cuba and Vietnam from even greater economic woes than they already face.

Three of every four barrels of oil used daily by the Comecon nations are Soviet, a total of 586 million barrels in 1979 at prices generally about 25 percent cheaper than OPEC oil. In return, the Soviets have been able to drive increasingly hard bargains for manufactured goods from the satellites and to demand East bloc participation in development schemes inside the Soviet Union that will chiefly benefit Moscow.

East bloc dependency on Soviet oil and gas strengthened Kremlin influence there precisely when detente might have offered the smaller buffer nations unique possibilities for forging new ties with the West at the expense of Moscow. Significantly, only Romania, with some petroleum reserves and foreign sources of its own, has been able to diverge from Moscow's politics.

While Poland and Hungary privately fretted over the Afghan invasion, and Bulgaria, Czechoslovakia and East Germany obediently applauded, only Romania felt bold enough after long years of testing its independence, to boycott the recent meeting of Communist parties called to back the invasion.

Kremlin energy influence extends into Western Europe, where several countries buy important amounts of Soviet natural gas, crude or refined products. Moscow is not shy about this leverage. A government commentator recently bluntly warned: "The White House turn toward Cold War and economic blackmail against the Soviet Union and other socialist countries creates a serious threat to the use by Western Europe and Japan of convenient external sources of energy."

By pegging their oil prices to world averages, the Soviets since the beginning of the petroleum crisis have reaped billions of dollars in hard currency, keeping pace with the rising costs of Western technology caused by OPEC price rises. Last year, for example, Moscow earned about $6 billion from oil exports, slashing its own trade deficit by more than two-thirds.

But in the 1980s, this rosy picture could well turn sour. Depleted fields in European Russia, and increasingly complicated conditions of exploration and exploitation in the Arctic Siberian wastes, combined with speedy but wasteful production methods there that have flooded many underground reservoirs with water, have slowed production growth even as domestic and foreign demand for petroleum rises.

Soviet petroleum reserves are a state secret, but Western estimates place them at 60 billion barrels and a Swedish firm has suggested they may be double that. However, the 1980 production target of 4.2 billion barrels is about 240 million below the original goal. The CIA cited these problems in its 1977 forecast that Moscow would become a net importer by 1982 of 3.5 to 4.5 million barrels daily.

That prediction has been challenged by some leading Western specialists and the CIA has revised the turnaround date to 1985 or later.

While bitterly denouncing the CIA, the Soviets are clearly alarmed by their own projections and are moving in various ways to bolster production and expand other energy sources. In April, the Council of Ministers and Central Committee announced an urgent four-year effort to intensify west Siberian oil development under the hand of Vladimir Dolgikh, who directs Soviet heavy industry.

The effort is also aimed at improving Siberian living conditions to help stem rapid turnover of experienced drillers, whose high departure rate from the fields after completing a usual three-year contract has brought serious lags in exploration. The Soviets are about 200 test wells behind plan.

"National oil output will peak in a relatively short time and then start to fall," Soviet specialist Alexander Krylov recently declared in one of the frankest admissions to date of Moscow's petroleum troubles. Senior planner V. Filanovsky has warned that the Tyumen region may not be able to meet the high annual production increases set by the state, saying there must be a major breakthrough there to maintain production increases.

These problems have affected Soviet-Comecon relations. Last summer, Moscow froze energy exports through 1985 at present levels, threatening new hardship for the Eastern bloc where inflation and low productivity have stifled growth, lowering incomes and bringing increased emigration to the West.

Later, Premier Alexei Kosygin, whose Council of Ministers runs the Soviet economy, relented, decreeing a 20 percent rise in Comecon energy supplies for the period. While much of this apparently will be in coal and electricity, Kosygin's about-face underscores the Kremlin's complex problems with its satellites, where an energy crisis could mean more political discontent and trouble.

With these difficulties increasingly evident, Western apprehension has risen over possible Soviet entry into the world oil market, or a drive for access to Persian Gulf supplies either by barter deals or military equipment-for-oil swaps.

Some months ago, while calling for a European conference to guarantee Persian Gulf supplies, a senior Soviet aide hinted the Soviet Union may become a Middle East oil customer in the future. There has been no further official comment on this trial balloon, but the Afghan intervention makes clear the Soviets would have little difficulty mounting a preemptive armed strike into the region to secure Iranian oil.

The Afghan adventure has stalled a recent Carter administration decision to aid the Soviets in their search for more oil. The White House has suspended sale of a $114 million advanced drill bit factory, but allowed the Soviets in early May to purchase a $5 million offshore drill rig for exploration around Sakhalin island in the Pacific north of Hokkaido, Japan. e

Meanwhile, the Soviets are searching vigorously for more reliable trade partners. In March, they awarded a $118 million contract to two French firms for deepwater rigs to hunt for oil in the Caspian Sea, where 40 percent of the reserves are too deep for even the best Soviet rigs.

In other parts of its energy management, the party has ordered massive new heat conservation and waste control programs for industry. It also set a 31 percent growth rate in atomic power through the decade, including accelerated use of fast-breeder reactors that can get 50 times as much energy from uranium as conventional reactors, but are virtually unproven as commercial power sources.

Although officials show increasing sensitivity to the question of atomic power sites, they face no public opposition over environmental or health issues such as in the West. This lack of a vocal opposition does not mean instant results, however, and many Western analysts predict the Soviets will have serious troubles as they press their atomic power expansion plans because of the difficult technology and exacting standards that must be met.

In fact, they point out, less than 4 percent of Soviet energy comes from atomic power now, ranking nuclear fuel well behind wood as a heating source for the nation.

The trouble-plagued coal industry offers few easy answers either, although Soviet coal reserves are enough to last more than 350 years at present rates of use. But most of this, like oil and gas, is in remote interior regions where three months of blazing, mosquito-filled summer is followed by bitterly cold winters.

Until the Soviets perfect long-distance ultrahigh-voltage electrical transmission, the stupendous coal reserves are likely to remain just that. The CIA has estimated coal production here will increase only about 1.3 percent annually through 1985, a drop from the already disappointing rates of the last decade.

Even the Soviet natural gas industry, a bright performer with 8 percent growth last year, faces similar problems as the sources move farther and farther from the industrial and population centers in the western Soviet Union.

An ambitious proposal to liquefy Yakutia natural gas and ship it to Japan and the United States is nowhere near final agreement. Meanwhile, Soviet plans to expand the relatively cheap importation of Iranian gas for domestic use while sending its own gas west for hard currency has been derailed by revolutionary Tehran, which has stopped shipments through the pipeline into the Transcaucausus and ceased construction of another pipeline project agreed to by the ousted shah.

In other times, the Soviets expanded their economy by the Stalinist solution of ordering workers into industry.

Today's Kremlin leadership has abandoned overt violence and threats to get people to work, but in the 1980s, even the pool of new manpower will suddenly shrink, presenting the party and its bureaucrats with new severe economic challenges.