After nearly a decade of stalking unseen underwater intruders along their coast, Swedish naval patrols report that the unexplained sonar contacts have stopped in the weeks following the collapse of the Soviet Union.
Military and government leaders say the coincidence supports their suspicion that Soviet submarines were responsible for the mysterious activity during much of the 1980s. But Gen. Bengt Gustafsson, the top Swedish military commander, said that high-ranking Russian naval officers continue to insist that they were not the culprits.
Gustafsson said in an interview that officers of the Russian Baltic Sea fleet told a Swedish delegation visiting Moscow last month that Soviet submarines were not involved in exercises inside Swedish territorial waters. In one incident in 1989, a Swedish patrol vessel fired depth charges at a suspected submarine south of Stockholm.
Gustafsson said that when the Swedish delegation provided details relating to the 1989 incident, including underwater reconnaissance that showed some sort of undersea vessel had been moving along the sea bottom, the Russians agreed that the evidence suggested activity by a submarine. "But they said it was not one of theirs," he said.
Asked to explain the denial by the Russian officers, Gustafsson said, "A former superpower has a lot of organizations capable of such activities." He did not elaborate, but aides suggested that he might have been referring to military intelligence agencies that worked independently of the Soviet navy.
In 1983, NATO officials said a flurry of activity off Sweden and Norway suggested the Soviet navy was testing the effectiveness of Scandinavian defenses. In the event of hostilities Soviet submarines based in the Baltic would have had to pass through Swedish waters to escape into the Atlantic.