Because of typographical errors, a sentence in an article yesterday about Soviet military difficulties in Afghanistan included incorrect numbers on insurgent forces. The sentence should read: Those forces are estimated at 50,000 to more than 110,000, divided among 100 or 200 uncoordinated groups.

The Soviet Union's top military officer, Marshal Nikolai V. Orgarkov, arrived yesterday in the capital of Afghanistan where he found military problems that begin to resemble those American forces faced a decade ago in Indochina.

There is no question that Soviet troops control the major Afghan cities, the main roads and the government in Kabul. The chance that the scattered bands of insurgents could somehow defeat the Russians is zero.

Nevertheless, according to the best estimates of U.S. specialists in global intelligence, the Soviet military is confronted with serious difficulties.These include the harassment by Afghan rebels who move about the countryside with random effectiveness, the defection of Afghan Army units who soldiers take their weapons over to the rebel side and the disappointing performance of some Soviet divisions.

Americans who remember the frustrations of the U.S. war in Vietnam may see some similarities in these developments reported by U.S. officials in Washington:

Intelligence officials say they have credible reports from rebel leaders that the Soviets have used napalm in some actions near Jalalabad.

The Soviets are operating squadrons of SU17, Mig21 and Yak28 fighter-bombers from bases in Afghanistan and nearby in the Soviet Union, using ground controllers to call in the air strikes as the United States did. The Soviets also have brought in 24 to 36 bigger TU16 bombers close to the border, but have used them thus far only for reconnaissance.

Aside from about 80,000-plus army troops in six divisions now in the country, there are said to be tens of thousands of individual military personnel -- officers, enlisted specialists and foot soldiers rather than entire units, that are now moving toward Afghanistan from all over the Soviet Union as replacements for the largely local reserve soldiers used initially for a 90-day stint.

The overall estimate is that 150,000 to 200,000 Soviet military men are, in one way or another, being affected by the Afghan invasion. While officials call this shift slight and say it is not making a serious dent in major Soviet forces in Europe or on the Chinese border, it reflects a growing call on military manpower.

Soviet casualties from all causes -- including sniper fire and highway accidents -- during the first month of the invasion are about 2,000 killed and wounded, an estimate which U.S. officials seem relatively confident about. Casualties continue to run about 500 a week, they report, and form letters sent home report the deaths but not where they took place.

The Soviet strategy now appears to be to stay in the key urban areas and provincial capitals, keep open the two main roads to the Soviet Union, protect the airfields and conduct limited counterinsurgency strikes from their main camps against pockets of rebel resistance.

U.S. specialists believe there are not enough Soviet troops in Afghanistan now to carry out countrywide sweeps and defeat the insurgent forces totally. Those forces are estimated at 50,000 to more than 100,000, divided among 10 to 20 uncoordinated groups, many of them tribal, and some of whom occasionally fight each other.

There is also some doubt that the Soviets ever will try the all-out sweeps since they are certain to raise their own casualties by pitting Soviet armored units not well suited to battling Afghan guerrillas in the harsh mountainous terrian.

Like Vietnam, there are also some surprises.

Soviet Mi-24 helicopter gunships, heavily armored and unable to get up very high because of the weather, are being shot down on occasion from above by rebels with machine guns in the mountains.

The two airborne divisions in Afghanistan are among the best in the Soviet army. But the four motorized rifle divisions, in the assessment here, have turned in "a dismal performance against lightly armed ragtag bands of bandits."

U.S. government officials say there is reliable information indicating the leadership in the Soviet defense ministry is very disappointed at their performance thus far.

The example cited is the three-week struggle of units of those forces to reach and take two provincial capitals -- Feyzabad and Taloqan -- in the extreme northeast of the country, a sensitive, mountainous area near the Soviet border.

Insurgents, now scattered through the countryside, used landslides, sniper fire and bridge demolition to thwart the Soviet advance.

Nevertheless, though the going may be slower than expected, specialists say there is no political or military evidence to suggest that the Soviets will back away and that there is every indication that they are in Afghanistan for the long run.

This spring could be a turning point. Warner weather will allow Soviet land and air power to be used more widely if Moscow gives the signal. U.S. specialists say there is no evidence to confirm reports of poison gas use, though the Soviets have gas warfare equipment with them and could use it in the spring in weather that makes it more effective.

For the moment, the Soviet divisions have their hands full and specialists see no evidence of any pending moves into neighborhing Iran or Pakistan. But greater use of military force this spring is the kind of thing U.S. officials believe could spill over the borders if the Soviets pursue, by ground or air rebels moving among Iran, Pakistan and Afghanistan.

Iran's president elect, Abol Hassan Bani-Sadr, said last week that Iran would aid the Afghan people with all means possible, including military means.

The U.S. officials say the Afghan insurgents are now "not hurting for weapons" and are getting them from Afghan army deserters. They claim the Afghan government army, which was in disarray and had 70,000 or 80,000 men before the Soviet invasion, is now down to roughly 30,000 men and that there is evidence the Soviets -- not trusting the army's loyalty -- are disarming units in many areas of the country. The Afghan air force also reportedly has been grounded.

Rebuilding a demoralized force into a loyal army to evidentually relieve the Soviet military presence, U.S. specialists estimate, will take one to three years if it can be done at all.

U.S. sources claim that last week an entire, 1,000-man regimental unit in western Afghanistan near Herat defected to the rebels with their heavy equipment and weapons as did a once-loyal army unit north of Kabul, which then reportedly raided the Soviet air base at Bagrame.

Whether Afghanistan will turn out to be the quagmire for the Soviets that Vietnam was for the United States or whether it will prove to be a successful thrust that establishes Soviet power near the oil-rich Persian Gulf is the key question.

Many U.S. government specialists seem to doubt the Russians will ever entirely defeat the insurgents, present a legitimate government that is accented by the population or reconstruct a loyal army Moscow is also concerned about driving Pakistan toward the United States and China.

But despite these problems, the specialists say it is clear that in the long run the Soviets will have a far greater voice and impact in the entire South west Asia region.

What worries these analysts most is that the Soviet powerplay has come while there are extremely weak governments in Iran and Pakistan, enabling Soviet pressure to be even more effective and holding out the prospect of completely unpredictable developments at any time.

Perhaps even more ominous, they say, is that the Soviets do not break precedent very often or easily and the move to use force outside the Warsaw Pact nations for the first time means a consensus within the Soviet leadership to take such a blod step.