The Road to Broken Alliances
The year 1939 witnessed a tragic chapter in European diplomacy when Western powers made solemn commitments to Poland that they would never truly honor. On March 31, Britain pledged to guarantee Polish security, followed by the Anglo-Polish Mutual Assistance Treaty on August 25. These agreements legally bound Britain to provide full military support if Germany attacked Poland. France had similarly committed to Polish territorial integrity through earlier agreements like the Locarno Pact, reinforced by a joint declaration with Britain on April 13, 1939.
Military planning appeared thorough on paper. The May 19 Franco-Polish military protocol detailed specific commitments: 60 French bombers would strike German targets immediately, ground forces would launch limited attacks within three days of mobilization, and full-scale offensives would commence by the fifteenth day. French Commander Maurice Gamelin even boasted about breaching the Siegfried Line. These promises created a false sense of security in Warsaw, masking the reluctance that would soon become apparent.
The Theater of Diplomacy
When Germany launched its blitzkrieg against Poland on September 1, 1939, the Anglo-French response revealed their true intentions. Rather than immediate military action, both governments explored diplomatic backchannels. French Foreign Minister Georges Bonet pursued Mussolini’s mediation proposal for a conference to revise Versailles Treaty terms, while Britain insisted on German withdrawal as a precondition. These maneuvers continued even as Polish cities burned.
The formal warnings delivered to Germany on September 1 at 9 PM (Britain) and 10 PM (France) contained identical language demanding cessation of hostilities. Crucially, diplomats immediately clarified these weren’t ultimatums but mere warnings – a deliberate weakening of position that signaled their unwillingness to fight. Only under intense domestic pressure did Britain issue a real ultimatum on September 3 at 9 AM, followed reluctantly by France at noon with a 5 PM deadline.
The Phony War Begins
Germany’s rejection of the ultimatums forced British (11 AM) and French (5 PM) declarations of war on September 3, joined by Commonwealth nations. This expanded the conflict globally but inaugurated what historians call the “Phony War” – eight months of inaction until May 1940. Despite possessing 1,760 (Britain) and 1,407 (France) combat aircraft, neither conducted meaningful air operations. France specifically forbade British raids on German industry, fearing retaliation, unaware this was precisely Hitler’s greatest fear regarding the Ruhr Valley.
The military imbalance made Western inaction particularly egregious. Germany had only 32 divisions on the Western Front, with just 11 being full-strength, while France mobilized 110 divisions. The incomplete Siegfried Line remained vulnerable. Yet Gamelin’s promised September 4 offensive became the symbolic “Saar Offensive” on September 8 – a 5-mile advance with no serious engagement. By October 16, French forces retreated to their starting positions. Britain dispatched just four divisions on October 11, long after Poland’s fate was sealed.
Global Reactions and Consequences
The international response mirrored this paralysis. On September 5, President Roosevelt declared U.S. neutrality, invoking Wilson’s WWI precedent. His September 20 proposals to Congress included arms embargoes and travel restrictions – measures that inadvertently aided Germany by limiting Allied access to American resources.
Meanwhile, the Soviet Union executed its own betrayal. After secret coordination with Germany, Stalin invaded eastern Poland on September 17 under the pretext of “protecting” Ukrainian and Belarusian minorities. The two-pronged assault by 40 divisions met limited resistance from Poland’s 25 border battalions. Within twelve days, Soviet forces advanced 250-350 km, capturing 300,000 prisoners while suffering minimal casualties. The September 28 German-Soviet Boundary Treaty formalized the fourth partition of Poland along the San-Bug-Narev rivers, with Lithuania becoming a Soviet sphere of influence.
The Legacy of Betrayal
This episode fundamentally shaped World War II’s course. The Western Allies’ failure to act allowed Germany to avoid a two-front war initially, while Soviet gains established Stalin’s western buffer zone. Poland became the first casualty of what Churchill later called “the unnecessary war” – unnecessary because earlier firm action might have deterred Hitler.
The cultural impact resonated deeply in Polish collective memory, fostering enduring distrust of Western guarantees. This trauma resurfaced during the Yalta Conference when Poland again found its fate decided by great powers. Modern parallels appear in debates about NATO’s Article 5 commitments, making 1939 a cautionary tale about the costs of hollow promises in international relations.
Strategically, the Phony War proved disastrous. It gave Germany time to consolidate Eastern gains before turning West in 1940, while Allied credibility suffered irreparable damage. The nine-month delay before serious fighting began arguably made France’s eventual defeat more likely, as it eroded military morale and public support for the war.
The 1939 Polish crisis remains a masterclass in failed deterrence, showing how legally binding treaties crumble without political will. It demonstrates that alliances without enforcement mechanisms become mere scraps of paper – a lesson that continues to inform geopolitical strategy to this day.