Soviets bomb Afghanistan to get `decent interval' for exit. Fear rebels' hold on major city will lead to Kabul regime's collapse

Like the United States in Vietnam, the Soviet Union is trying its version of ``Rolling Thunder'' to find an ``honorable'' way out of Afghanistan, says a well-placed US official. Over the past several days, strategic bombers based in the Soviet Union and newly arrived high-performance MIG-27 combat aircraft have been bombing Afghan resistance positions in southwestern Afghanistan.

In addition, Tass acknowledged yesterday that the Afghan Army has received long-range rockets to retaliate against rebel missile attacks.

This is the first known use of the sophisticated ``Backfire'' bombers and MIG-27s in Afghanistan, US officials say. Washingotn delivered a firm protest to Soviet Ambassador Yuri Dubinin late Monday.

The US views the bombings against guerrilla positions around the city of Kandahar as a violation of Soviet promises not to undertake offensive operations. US officials say the attacks from inside the Soviet Union against areas from which Soviet troops have withdrawn is a violation of the spirit of the Geneva accords on Afghanistan.

But so far, US officials say, the Soviets still seem committed to having all their troops out of Afghanistan by Feb. 15. What might slip, they say, are Soviet unilateral commitments to begin the second wave of military pullouts on Nov. 15 and to complete that pullout by the end of 1988.

The military escalation, US specialists say, is rooted in Moscow's inability to find a formula guaranteeing at least a ``decent interval'' between the pullout of Soviet troops and the fall of the pro-Moscow regime in Kabul.

``Remember US frustration near the end of the Vietnam negotiations,'' one ranking official says. ``We unleashed our B-52s for weeks on North Vietnam in an attempt to get a better solution. Now we're talking about the Soviet Union. They're on the way out of a battle they don't consider they lost.'' But ``they're shooting hard,'' because they have no alternatives.

Basically, another key official says, the resistance is ``rolling up the countryside'' with military victories, and the Soviets are urgently trying to stop them. A third specialist adds that resistance successes are increasing the factionalism in the pro-Soviet regime.

``This is an effort to boost morale in Kabul and increase the incentive of the resistance to negotiate,'' says a US specialist on the region. ``More generally, Moscow is demonstrating to everyone that it will use its power to prevent a major change, such as the toppling of the Kabul regime, at least before it leaves.''

The Soviet bombings are specifically aimed at breaking the resistance stranglehold that has been tightening around Kandahar, one of three major Afghan cities. If Kandahar falls, one specialist says, other government garrisons could melt away and the whole regime go belly up before the remaining 50,000 Soviet troops are out.

Indeed, US officials say the Soviets are still scrambling to come up with any workable political solutions. They are pushing the idea of a coalition government. But their effort to promote the current prime minister of Afghanistan, Muhammad Hassan Sharq, as a possible coalition leader has fallen on deaf ears, US officials say.

Though Mr. Sharq is not an Afghan Communist Party member, one explains, he is widely perceived as a ``longstanding asset of the KGB.'' ``Even many of the so-called Afghan `neutrals' - exiles not fighting in the resistance - see this as worse than being a party member.''

US officials say the Soviets still don't understand the realities of Afghanistan and are making a vain effort to save a role for their allies. ``The Soviets continue to talk about power-sharing, but the resistance is only willing to talk about power transfer,'' sums up a US official. ``And so far the Soviets are not willing to talk about that.''

The resistance, another adds, is not interested in a political settlement with Moscow's allies since they see victory within reach.

Kabul Prime Minister Sharq and an Afghan resistance delegation will be at the United Nations this week to present their rival plans for political reconciliation. Sharq is expected to offer talks on power-sharing, while the guerrilla alliance will put forward a plan for election of a national council that would then choose a new government.

The guerrillas are ready to talk with the Soviets, US officials say, when and if Moscow is willing. At present, they add, the resistance is showing military restraint. ``They have missiles, and accurate ones, all over the country,'' one US official says, ``but they are holding up on hitting the Soviets.''

That could change as could the US attitude. So far, the US is warning Moscow and counseling a change of strategy. But it is also watching carefully and intends to honor its commitments not to allow Soviet military supplies or actions to put the guerrillas at a disadvantage, officials say. More basically, if Washington saw anything that suggested Moscow would not have its troops out of Afghanistan by Feb. 15, ``it would be a new ball game,'' says one key official.