What agreement was made in 1939 to ensure a temporary truce between nations prior to the onset of World War II?

The agreement made in 1939 to ensure a temporary truce between nations prior to the onset of World War II is the Non-aggression pact. This pivotal agreement, specifically between Germany and the Soviet Union, allowed both nations to refrain from attacking each other and included the secret protocol to divide Eastern Europe into spheres of influence. This pact essentially facilitated Germany's ability to invade Poland without fear of Soviet intervention, thereby marking the beginning of World War II.

The Lend-lease agreement, while significant, was established later in 1941 and focused on providing military aid to Allied nations rather than establishing a truce. The Atlantic Charter, created in 1941 by the United States and Great Britain, outlined their goals for post-war peace and was not related to a temporary truce before the war began. The Four Freedoms, articulated by President Franklin D. Roosevelt in 1941, defined the essential freedoms that should be guaranteed globally but were also not directly connected to the truce prior to World War II.