Open fighting between Finnish and German troops ended in November 1944, but the Germans still occupied a tiny sliver of Finland in the country's north-western "arm" at Kilpisjarvi. With Germany's final defeat imminent, Finland declared war on Germany on 4 March 1945 - the Allies had declared this a pre-requisite for United Nations membership. To make sure that Finland could claim to have liberated herself from the Nazis, the government ordered Lt. Gen. Hjalmar Siilasvuo to drive out the last German outposts. As Soviet troops fought their way into the heart of Berlin, far to the north Finnish soldiers removed the last German outpost from Finland.

This battle was waged mostly by young conscripts who had been drafted after the armistice with the Soviet Union and had not seen combat; it is still the "Children's Crusade" in Finnish histories of the war. The Germans put up surprising resistance, but the Finns broke through their fortified line and drove them back into Norway. Finland became a founding member of the United Nations and the only former member of the Axis to end the war with no foreign troops on her soil. The Finns stacked their arms and embarked on six decades of peaceful coexistence with their neighbors.