Why did Stalin sign the nonaggerssion pact in 1939?

Stalin signed the Non-Aggression Pact with Nazi Germany in 1939 primarily to secure the Soviet Union's western borders and gain time to strengthen its military capabilities. The pact, which included secret protocols for dividing Eastern Europe, also aimed to prevent a two-front war and allow the USSR to expand its influence in the region. Additionally, it provided a temporary buffer against potential aggression from Germany, giving Stalin a strategic advantage in the unfolding geopolitical landscape.