The limited withdrawal of Soviet troops from Afghanistan, announced today, is a minor reflection of the new Kremlin leadership's most underestimated achievement: effective political control of the powerful Soviet military.

Tables have turned since the 1979 Soviet invasion of Afghanistan, when Leonid Brezhnev, representing an ailing Kremlin gerontocracy, contended with what was clearly an influential military command. But defense minister Dmitri Ustinov died, chief of staff Nikolai Ogarkov was demoted, and other powerful officers retired.

Since Ustinov's death in 1984, the civilian leadership has denied the Defense Ministry full voting rights in the ruling Politburo for the first time since the early 1970s. According to western analysts in Moscow, the limits put on the military within the political hierarchy have paved the way for controversial decisions, including today's announcement of a limited pullout from Afghanistan.

In recent weeks, the Kremlin has broached arms control compromises that clash with longstanding military policy. And the ruling body has begun to drain Soviet defense industries of brainpower -- and perhaps resources -- through key decisions that a determined military resistance could have prevented, according to these analysts.

This has been accompanied by what appears to be a surprising public collaboration between senior military and political officials. To a western observer, a striking example is their joint involvement in Soviet leader Mikhail Gorbachev's policy of public diplomacy.

Col. Gen. Nicolai Chervov, the head of the armed forces general staff directorate, appeared before journalists here in June with a sweeping promise to allow westerners into the East Bloc all the way to the Urals to inspect military installations.

There was a catch, of course.

The on-site inspections would be permitted only if NATO agreed with other proposals outlined by Gorbachev and endorsed by the Warsaw Pact last month, calling for reductions of Soviet and U.S. troop and nuclear arms levels in Europe. The proposals have not been offered in any negotiating forum.

Still, Chervov's support for such a blanket call for cutbacks -- and the fact that he gave a press conference at all -- illustrates an unusually public teaming of the military and Gorbachev to boost the latter's image as a proponent of disarmament.

The plan Chervov advocated would involve on-site inspections that could loosen the iron grip the Soviet military has kept on access to its operations since World War II. Only 16 months ago, a Soviet soldier shot a U.S. Army major dead for peering into a Soviet military facility in East Germany.

Under Gorbachev, top brass -- including the chief of the general staff, Gen. Sergei Akhromeyev -- have taken on public relations duties, often sharing a podium with governmental or party spokesmen. Chervov has fielded reporters' questions in Moscow, Washington, London and Geneva. He and Akhromeyev are featured regularly in press conferences here, attacking President Reagan's positions on arms control and casting the Soviet Union as a champion of arms control.

In their own way, the Kremlin's civilians have paid homage to the military, too, perhaps to preclude a backlash. Under Gorbachev, Soviet soldiers fighting in the Afghanistan war have been depicted as heroes in the media here. Not too long ago, the 115,000 Soviet troops there were hardly mentioned at all.

Offstage, the Kremlin leadership has demonstrated its control over the military by keeping Defense Minister Sergei Sokolov off the ruling Politburo. In the past year, five new Politburo members have been named while Sokolov remains a candidate member. His immediate predecessors in the job were Politburo members.

The gradual process of bolstering civilian influence on the Soviet military could have major implications for the projected U.S.-Soviet summit. A stronger military voice would be expected to represent a conservative force in U.S.-Soviet negotiations.

As for the Kremlin's proposed one-third cut in nuclear warheads -- put forward in Geneva June ll -- that collides with the military's traditional stance against armament reductions of any kind.

The extent of Soviet military involvement in consultation on arms negotiations is murky. In an unusual move last September, the party newspaper Pravda publicized a meeting between the Kremlin's leaders and the Soviet negotiators at the Geneva arms talks.

More revealing than those included in the list of those present -- Gorbachev, Sokolov, President Andrei Gromyko, Foreign Minister Eduard Shevardnadze and KGB Director Victor Chebrikov -- was the exclusion of Chief of Staff Akhromeyev. Sokolov, the only non-Politburo member, was also the only military voice represented.

The leadership has redeployed several top defense industry personnel, threatening to drain the military-industrial complex's talent over the long run. Leading Politburo member Lev Zaikov, Prime Minister Nikolai Ryzhkov, and planning director Nikolai Talyzin all made their early careers in the defense industry. Ryzhkov has stacked the Cabinet's staff with defense industry managers from his native Sverdlovsk, one of the military-industrial strongholds.

The purpose must be to duplicate the successes of the military economy -- including efficient management and high growth -- in the flagging civilian economy. Gorbachev has stressed that a U.S.-Soviet arms control accord and a stable international climate would allow Moscow to focus on domestic economic reform. In the end, economic acceleration would enhance both the civilian and the defense economies, Gorbachev assured Central Committee members last month.

But western analysts here see a tug-of-war for resources developing. And they say the Reagan administration's request for a $320 billion defense budget has strengthened the incentive here for the military to seek more resources.

As for the military services, in contrast with the defense industry, they have clung tightly to the political strongholds held when Gorbachev took office.

The military has buttressed itself against sackings that have wracked nearly every ministry. Aside from Navy minister Sergei Gorschkov, all of the top military officials have remained in place.

Following an arm wrestle over seats on the powerful Central Committee, the military's representation remained intact, with 7.5 percent of the members.

Among those returned to the body were Ogarkov, who was ousted from the deputy foreign minister's post in 1984, Gorschkov and Vladimir Tolubko, both retired senior military officials. In the three, western analysts see the makings of a potential military comeback into the political ranks.

So far, any military grumbling over the new leadership has seemed low-key. Last year's Geneva summit -- Gorbachev's first venture into superpower politics -- was assessed with only faint praise by Soviet military writers.

Some key military officials reportedly told U.S. retired general David Jones, the former chief of staff then visiting Moscow, that they were dissatisfied with the summit results. More recently, some military dissatisfaction with the current Soviet ban on nuclear testing seems apparent. A mid-level military official in Moscow recently told Swedish diplomats that he had not favored Gorbachev's third extension of the bans, announced in May.

Western analysts cite pressure from the military as the main brake on Moscow's go-ahead for a second summit. "It is the military that is behind Gorbachev's calls for 'concrete results' at the summit," one senior western official said. "All the rest probably feel that the merits of a Gorbachev trip to Washington stand on their own."

Despite its show of public flexibility on controversial issues such as on-site inspection, the Kremlin's civilian leadership can be seen taking care to protect the security interests of the military. In April 1985 then-ambassador to Washington Anatoliy Dobrynin made a startling offer to allow western inspection of the controversial Krasnayarsk radar facility. Thereafter, the issue was dropped.

The Afghan veterans have received top honors, the links to military allies Libya and Syria have remained intact, and Marshal Sokolov, on his 75th birthday earlier this month, received the Order of Lenin.

Some western analysts see an effort at work to keep relations steady between party officials and the military. Others contend that in Soviet society, the interests of the military and the party are the same.