The Agreement of Friendship, Cooperation, and Mutual Assistance of 1948, also known as the YYA Treaty from the Finnish Ystävyys-, yhteistyö- ja avunantosopimus, was the basis for Finno–Soviet relations from 1948 to 1992. It was the main instrument in implementing the Finnish policy called Paasikivi–Kekkonen doctrine.

Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, opposite Estonia. Finland covers an area of 338,145 square kilometres (130,559 sq mi) and has a population of 5.6 million. Helsinki is the capital and largest city. The vast majority of the population are ethnic Finns. The official languages are Finnish and Swedish, of which 84.9 percent and 5.1 percent of the population speak the first as their mother tongue. Finland's climate varies from humid continental in the south to boreal in the north. The land cover is predominantly boreal forest biome, with more than 180,000 recorded lakes.