Moscow — The Soviet Union signaled Thursday that an Afghan settlement is close but not yet final. In an obscurely phrased joint statement issued at their talks in the Soviet city of Tashkent, Soviet leader Mikhail Gorbachev and Afghan President Najibullah declared their belief that the last obstacles to a settlement had been removed.
This implied that Moscow had dropped its objection to a United States demand that both sides either cease military aid to the belligerents, or be allowed to continue it after a peace accord.
Hours after the declaration, however, a Soviet spokesman said in Moscow that ``a process was under way,'' but that situation was still ``very fluid.''
[US officials interpret the joint communiqu'e as a clear signal that Moscow has accepted the US proposal for symmetry. ``It looks like the Soviets have agreed to wink'' at covert US military aid to the Afghan resistance as long as they supply their allies, a senior US official in Washington said.]
The joint Soviet-Afghan statement announced that if the long-stalled Geneva negotiations on Afghanistan are concluded quickly, Soviet troops will begin to leave Afghanistan on May 15.
In early February, Mr. Gorbachev declared that the estimated 115,000 Soviet troops in Afghanistan would be withdrawn over a period of nine months.
A preamble to the joint statement described the Gorbachev-Najibullah talks as marking ``a new stage'' in Soviet-Afghan relations. This term in the past has implied delicate and difficult discussions.
A similarly termed meeting between the two men in late 1986 was quickly followed by an abrupt shift in Afghan government policy - a six-month cease-fire and an effort by Kabul to reach out to both its own population and the guerrillas.
In Thursday's statement, the two leaders called for the immediate signing of an Afghan agreement in Geneva. They also spoke of ``the constructive cooperation'' of all sides involved in an Afghan settlement.
Four days ago, Soviet Foreign Minister Eduard Shevardnadze had complained of the ``unconstructive'' attitude of Pakistan and the US.
The Gorbachev-Najibullah talks, which came as a complete surprise to foreign and Soviet observers, follow four days of consultations in Kabul between Dr. Najibullah and Mr. Shevardnadze. Another senior Soviet official, First Deputy Prime Minister Vsevolod Murakhovsky, has also been in Kabul this week discussing Soviet-Afghan economic cooperation.
Mediated talks on Afghanistan ground to a halt in Geneva late last month. The main sticking point was a US demand for ``symmetry'' in the superpowers' military aid to their respective allies.
In other words, Moscow should either cease arms supplies to Kabul, or agree to continued US military aid to the antigovernment guerrillas. Moscow dismissed this. The proposal interfered in Moscow's bilateral relations with a legal government, and attempted to equate the Kabul regime with the antigovernment guerrillas, Soviet leaders complained. Moscow threatened to conclude a separate agreement with Kabul and withdraw unilaterally.
The Soviet acceptance of symmetry would constitute yet another major concession made in order to extricate its troops from Afghanistan. Coming as it does at a time when Gorbachev is beset at home with ethnic disturbances and is possibly engaged in a serious struggle with political opponents, the concession would indicate a broad degree of support inside the Soviet leadership for an Afghan pullout.
The concession is in one respect, however, less dramatic than it might seem. While firmly declaring the legitimacy of the Kabul government, Moscow has nonetheless been signaling to its own people that their Afghan allies are a lost cause.
Soviet observers here say openly that the pro-Soviet People's Democratic Party of Afghanistan (PDPA) has failed to win a popular following. They add that the guerrillas enjoy widespread support among the Afghan masses. They admit that they do not know what will happen after Soviet troops leave.
The fundamental assumption of most Soviet observers of Afghanistan appears to be that Kabul's armed forces - 50,000 troops, plus internal security units - will at least give the PDPA a bargaining chip with which to negotiate a role for itself in a future government.
Soviet specialists are also hoping that the seven guerrilla factions will quickly turn against each other.
And, perhaps most ironically, some Soviets are hoping that the traditional Afghan power structure - tribal leaders and Islamic clergy - will reassert its strength, thereby undercutting the Islamic fundamentalist wing of the guerrilla movement.
For the next year or so, however, Moscow needs a government and army in Afghanistan that are reasonably well disposed to the Soviet Union. When the Soviet troops pull out, some Soviet observers note with a trace of trepidation, their withdrawal will be covered by the Afghan armed forces.
[In Washington, even as Reagan administration officials await official Soviet affirmation of a deal, their attention is shifting to selling the agreement to Congress. They expect strong opposition from legislators who worry that the accord harms the Afghan resistance.]