The Kremlin seems to have a yen -- perhaps, billions of them -- to repair its tattered relations with neighboring Japan. A recent Soviet diplomatic overture, rebuffed in Tokyo, is being linked by Asian sources here largely to Moscow's desire for expanded trade with Japan.
Among the economically developed allies of the United States, Japan has been one of the most sympathetic to the American call for an embargo on high-technology exports to the Soviet Union, in protest over the Soviet invasion of Afghanistan.
Recently released Soviet figures show a slight increase in trade with Japan for 1980. But a commentary by the official Soviet news agency noted a sharp decline in the "rate of increase": Japan has dropped from second to fifth place as a source of Soviet imports from the noncommunist world.
In the short run, the Soviets seem interested in getting large-diameter Japanese steel components for a huge pipeline that would carry Siberian gas to Western Europe and to the European section of the USSR.
The project is a central pillar in a Soviet strategy to shift both domestic energy consumption and exports away from oil to natural gas and other energy sources
Diplomats here say the Soviet Union, now bargaining with West German and other European concerns over interest rates in financing the $10-15 billion project, also has shown signs it may seek Japanese help in this area as well.
"With the West Germans, the Soviets have begun playing what might be called the Japanese card," said on West European source who is following the progress on the mammoth gas venture.
Japanese sources here say a Soviet delegation is slated to visit Tokyo later this month for talks on the pipeline project. A second Soviet delegation is expected in Japan in April to discuss a new trade accord linked to Moscow's current fiveyear economic plan, for the years 1981 through 1985.
The problem for the Kremlin is to insulate commercial ties with the Japanese from an overall worsening of Soviet- Japanese relations.
Some analysts here also suggest Moscow may be playing to business interests in Japan in hopes of prodding a softening of the Tokyo government's attitude toward the Soviet Union.
Reports from Tokyo March 16 said the Soviet ambassador there had relayed a Kremlin proposal for improved relations. And he reportedly repeated Soviet President Leonid Brezhnev's public call for talks on Asian "Military confidence" measures, including advance notification of military maneauvers.
The ambassador is said to have sought a face-to-face meeting on these issues with the Japanese prime minister. That was turned down, and Japanese officials said in effect they were in no mood for sweet talk from Moscow while the Soviets were refusing to budge from four disputed islands north of Japan which they have occupied since World War II.
It was primarily this issue that undermined Soviet-Japanese talks on a bilateral treaty several years ago and ultimately prodded Japan to sign a treaty with China instead.
It is an issue on which the Soviets seem staunchly uninclined to compromise. Diplomats suspect Moscow fears this could set a bothersome precedent in a vast superpower built largely on the legacy of Russian imperial gains or on lands the Soviets have won through war.
Current Soviet-Japanese relations are also complicated by Japan's increasingly close ties with the US and with China. The Soviets seem concerned, in the long run, over the possible emergence of a triangular threat from populous rival China, the economically advanced Japanese, and the United States.
Recent reports from Tokyo Speak of a strengthening of Soviet military installations on the coast opposite northern Japan.
The official Soviet press has been attacking what it sees as a US-sponsored militarization of that island state.
President Brezhnev's keynote speech to the Soviet Communist Party congress here in February attacked both China and Japan, the latter for "playing up to the dangerous plans of Washington and Peking." He also said he wanted good relations with both countries.