2 history quick questions

This country made effective use of ski troops in the Winter War with
the Soviet Union. Martti Ahtisaari, who won the Nobel Peace Prize in 2008
served as this country’s president in the 1990’s. During the Cold War, it
prospered economically despite its precarious location close to Leningrad.
For ten points, name this country that was the site of the 1975 Helsinki Accords.