The invasion of Poland in September 1939, which marked the beginning of World War II, was not a sudden event but rather the culmination of intricate diplomatic maneuvers and secret agreements. Central to these preparations was the Molotov-Ribbentrop Pact, a non-aggression treaty signed between Nazi Germany and the Soviet Union. This pact, concluded on August 24, 1939, effectively neutralized the possibility of Soviet opposition to Germany's planned
campaign against Poland and laid the groundwork for the country's partition.
Secret Protocols and Spheres of Influence
The Molotov-Ribbentrop Pact contained secret protocols that delineated the division of Eastern Europe into spheres of influence for the two signatory powers. Specifically, Germany and the Soviet Union agreed to partition Poland, with the western one-third of the country designated for Germany and the eastern two-thirds for the Soviet Union. This agreement meant that war with Poland became imminent, as Germany had secured Soviet non-interference.
Prior to this pact, the Soviet Union had engaged in negotiations with France and the United Kingdom regarding a potential anti-German alliance. However, the Soviet conditions for such an agreement, which included the right for Red Army troops to pass through Polish territory, were met with resistance from Polish leaders. The Polish government, fearing that Soviet troops would not leave once on their soil, refused to agree to any arrangement allowing Soviet forces to enter Poland. This refusal ultimately pushed the Soviets towards Germany's offer.
German Diplomatic Aggression and Polish Mobilization
Leading up to the pact, Germany had already demonstrated aggressive diplomatic tactics. On April 28, 1939, Hitler unilaterally withdrew from both the German-Polish Non-Aggression Pact of 1934 and the Anglo-German Naval Agreement of 1935. Talks concerning Danzig and the Polish Corridor subsequently broke down, leading to a period of diplomatic silence between Germany and Poland. During this time, Germany learned that France and Great Britain had failed to secure an alliance with the Soviet Union against Germany, and that the Soviet Union was interested in an alliance with Germany against Poland. Hitler had already issued orders to prepare for a military solution to the "Polish problem" through the "Case White" scenario.
On August 29, Germany issued a final diplomatic offer, demanding that a Polish plenipotentiary arrive in Berlin within 24 hours to negotiate. The British regarded this as an unacceptable ultimatum, reminiscent of how Emil Hácha had been forced to sign away Czechoslovakia. When Polish Ambassador Lipski met with German Foreign Minister Joachim von Ribbentrop on August 31, he indicated Poland's willingness to negotiate but lacked the full power to sign an agreement, leading to his dismissal. German radio then broadcast that Poland had rejected Germany's offer, providing Hitler with a pretext to order the invasion.
The Impact of the Pact on Poland's Fate
The Molotov-Ribbentrop Pact fundamentally altered the geopolitical landscape and sealed Poland's fate. With the Soviet Union as a non-belligerent, Germany was free to launch its invasion without fear of a two-front war. The subsequent Soviet invasion of Eastern Poland on September 17, in accordance with the secret protocol, rendered the Polish defense plan obsolete. The Polish government concluded that defending the Romanian Bridgehead was no longer feasible and ordered an emergency evacuation of all troops to neutral Romania. The campaign ended on October 6, with Germany and the Soviet Union dividing and annexing the entirety of Poland under the terms of the German-Soviet Frontier Treaty. This treaty further adjusted the territorial division, placing Lithuania within the Soviet sphere and moving the agreed boundary east from the Vistula to the Bug River, solidifying the partition of Poland and authorizing further joint action to control the occupied territory. An earlier idea of retaining a residual Polish state was abandoned, underscoring the comprehensive nature of the partition agreed upon by the two powers.
