On November 30, 1939, the Soviet Union initiated military operations against Finland, marking the beginning of the Winter War. The Red Army launched attacks across Finland's northern borders while also conducting air raids on Finnish cities, including Helsinki. The incursion was spurred by the Soviet leadership's concerns over national security, particularly following the establishment of close ties between Finland and Nazi Germany. The USSR sought to expand its influence in the region and demanded territorial concessions from Finland, which were rejected. Consequently, the Red Army's full-scale invasion was a response to these failed negotiations. Finland found itself unprepared for such an overwhelming assault, yet the Finnish military, composed of well-motivated and resilient troops, mounted a fierce defense against the better-equipped Soviet forces. The Winter War quickly became a conflict defined by guerrilla tactics, fierce snow battles, and the harsh winter conditions that the Finnish soldiers were better adapted to handling. Despite the technological and numerical superiority of the Soviet forces, Finnish troops utilized their knowledge of local terrain to execute successful defensive strategies.