After the Nazis rose to power in Germany in 1933, relations between Nazi Germany and the Soviet Union began to deteriorate rapidly. Trade between the two sides decreased. Following several years of high tension and rivalry, the two governments began to improve relations in 1939. In August of that year, the countries expanded their economic relationship by entering into a Trade and Credit agreement whereby the Soviet Union sent critical raw materials to Germany in exchange for weapons, military technology and civilian machinery. That deal accompanied the Molotov–Ribbentrop Pact, which contained secret protocols dividing central Europe between them, after which both Nazi forces and Soviet forces invaded territories listed within their "spheres of influence". The countries later further expanded their economic relationship with a larger commercial agreement in February 1940. Thereafter, Germany received significant amounts of critical raw materials necessary for its future war efforts, such as petroleum, grain, rubber and manganese, while sending weapons, technology and manufacturing machinery to the Soviet Union. After unresolved negotiations regarding a potential Soviet entry into the Axis Pact, the two governments settled several disputes and further expanded their economic dealings with the January 1941 German–Soviet Border and Commercial Agreement. Economic relations between the two countries were abruptly terminated when Germany invaded the Soviet Union in June 1941, in violation of the Molotov–Ribbentrop Pact. Background Traditional commerce, World War I and Russian Revolution Germany did not lack natural resources, including the key raw materials needed for economic and military operations. Before World War I, Germany had annually imported 1.5 billion Reichsmarks of raw materials and other goods from Russia. However, the economies of the two countries differed greatly before World War I. Germany had grown into the second-largest trading economy in the world, with a highly skilled workforce largely dominated by the private sector. While Imperial Russia had rapidly modernized by tenfold in the fifty years before the war, its economy still relied heavily upon state orders and its industry was closely regulated by the Tsarist state. Russian exports to Germany fell sharply after World War I. In addition, after the Russian Revolution of 1917, the young communist state assumed ownership of all heavy industry, banking and railways, while the 1921 New Economic Policy left almost all small-scale production and farming in the private sector. The war-ravaged German economy struggled to return to pre-war levels, with inflation also taking its toll in 1923. In