DEFENSE : Cream of Soviet Military Is Flowing North : After pulling out from Central Europe, the Kremlin fortifies its flank facing Finland, Norway and Sweden.

At an air base in Eastern Europe, Hungarian officials not long ago were startled to see Soviet airmen painting out the Soviet air force’s camouflage markings on SU-24 Fencer long-range attack aircraft and painting on the gray-and-white colors of the Soviet navy.

Soon after, the squadron of 40 planes flew to a new base on the Kola Peninsula, in the Arctic region north of Leningrad where the Soviets’ most modern warships--nuclear missile submarines, aircraft carriers and cruisers--rest in ice-free ports.

The shift of those fighter-bombers was the first sign that the Soviets, while accepting their withdrawal from the central zone of Europe, had no intention of similarly weakening their northern flank, which faces the Nordic nations of Finland, Norway and Sweden.

In fact, the Soviets seem determined to strengthen their presence in that region.

Two of the three Red Army divisions that have abruptly been converted into “naval infantry” and “coastal defense” forces--a move to exempt them from the new conventional arms reduction treaty--are stationed in the military districts facing the Nordic countries.

These additional aircraft--plus more up-to-date tanks and other equipment that Moscow has transferred from its former East European legions--have actually increased the power of Soviet forces on the once “quiet flank” of the North Atlantic Treaty Organization, officials say.

“As a consequence,” says Norway’s Defense Minister, Johan Jorgen Holst, in a typical Scandinavian understatement, “the ‘peace dividend’ will not be as large in the northern region.”

Europe’s northern flank has long been a hostage to U.S.-Soviet confrontation in the Cold War. In the 1960s, Moscow embarked on a huge buildup of its Northern Fleet, which operates in the country’s only year-round ice-free ports. Today, most of the Soviet navy’s newest warships are home-ported at Severomorsk and 10 other deep harbors there.

This massing of military power--perhaps the greatest regional concentration of nuclear weapons in the world--is a geographical accident that has nothing to do with the neighboring Nordic nations.

The strategic nuclear missiles in Soviet submarines are aimed at the United States. Soviet attack submarines are intended to cut Atlantic sea lanes between the Americans and their NATO allies. The Soviet surface fleet--including new aircraft carriers and cruisers--was built primarily to protect the submarines.

But to guard these enormous assets, Moscow’s military is positioned to take over at least the northern part of Norway--which itself it a member of NATO--in time of war. The Norwegians have merely 5,000 troops in the area--the bulk of their standing army.

By contrast, the Soviet troop deployment on the Kola Peninsula is at least 10 times that size and offensively poised, with airborne assault units among its army divisions, amphibious landing capabilities and naval infantry.

Western strategists believe that in a crisis the Soviets would also move on Norway through Finland, exploiting that country’s flatter terrain. Sweden also lies on the road to Norway. The Soviets got caught in a famous 1981 incident--a Soviet submarine on the rocks off a key Swedish naval base--but they brashly continued underwater probes of Swedish coastal defenses.

The Soviets’ Nuclear, Nordic Front

Map shows massing of Soviet military power near Norway, Sweden and Finland. The collection of modern warships, nuclear missile submarines, aircraft carriers and cruisers-in ice-free ports-is perhaps the greatest regional concentration of nuclear weapons in the world. It is not designed to threaten Nordic regions, per se, but to protect Soviet attack capabilities aimed at the United States. Pechenga: Conventional submarines and escort ships Litsa Guba: Strategic, tactical and attack submarines Ara Guba: Nuclear submarines and escorts Port Vladimir: Minor surface combatants (minesweepers, etc.) Sayda Guba: Strategic submarines Olenya Guba: Strategic and research submarines Teriberka: Patrol ships Polyarnvy: Minor surface combatants, conventional submarines Pala Guba: Auxiliaries Severomorsk: Naval main base Rosta: Shipyards for maintenance and modernization Gremikha: Nuclear submarines Severodvinsk: Workshops for construction and modernization of submarines; base for minor surface combatants and patrol ships

Source: Norwegian Atlantic Committee