On 27 October 1981 , a Whiskey-class submarine ( '' U 137 '' ) from the Soviet Union ran aground close to the naval base at Karlskrona in the southern part of the country . Research has never clearly established whether the submarine ended up on the shoals through a navigational mistake or if an enemy committed espionage against Swedish military potential . The incident triggered a diplomatic crisis between Sweden and the Soviet Union . Following the 1986 assassination of Olof Palme and with the end of the Cold War , Sweden has adopted a more traditional foreign policy approach . Nevertheless , the country remains active in peace keeping missions and maintains a considerable foreign aid budget
1986 assassination of Olof Palme
Assassination of Olof Palme
Sweden