Conflict and Tension 1918-1939Topic Summary
Topic Summary: Outbreak of War, 1939
Part of Outbreak of War — GCSE History
This topic summary covers Topic Summary: Outbreak of War, 1939 within Outbreak of War for GCSE History. Revise Outbreak of War in Conflict and Tension 1918-1939 for GCSE History with 8 exam-style questions and 5 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 14 of 14 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 14 of 14
Practice
8 questions
Recall
5 flashcards
Topic Summary: Outbreak of War, 1939
Key Terms
- Nazi-Soviet Pact: Non-aggression treaty (23 Aug 1939) — secret protocol divided Poland between Germany and USSR
- Polish Corridor: Strip of Polish land separating Germany from East Prussia — one of Hitler's stated justifications for invading Poland
- Danzig: German-speaking "Free City" under League protection — Hitler demanded its return to Germany
- British guarantee: March 1939 promise to defend Polish independence — formally abandoned appeasement
- Two-front war: Hitler's strategic nightmare — the Pact eliminated it
Key Dates
- Mar 1939: Hitler seizes rest of Czechoslovakia; Britain guarantees Poland
- 23 Aug 1939: Nazi-Soviet Pact signed (Molotov-Ribbentrop)
- 1 Sep 1939: Germany invades Poland
- 3 Sep 1939: Britain and France declare war on Germany
- 17 Sep 1939: USSR invades Poland from the east
Key People
- Adolf Hitler: Invaded Poland expecting Britain and France to back down — fatal miscalculation
- Joseph Stalin: Signed Pact to buy time and gain territory; had been excluded from Munich (1938)
- Vyacheslav Molotov: Soviet Foreign Minister who signed the Pact
- Joachim von Ribbentrop: German Foreign Minister who signed the Pact
- Neville Chamberlain: Issued guarantee to Poland; declared war 3 September 1939
Must-Know Facts
- Nazi-Soviet Pact signed 23 August 1939 — just 8 days before Germany invaded Poland
- Secret protocol divided Poland: Germany took west, USSR took east (invaded 17 Sep)
- Hitler expected Britain and France to back down over Poland — his fatal miscalculation
- Britain declared war 3 September 1939, two days after the German invasion
- HVALP mnemonic: Hitler's aims, Versailles, Appeasement, League failure, Pact
Cross-Topic Links
- → Topic 21 (The Big Three): The outbreak of war in September 1939 vindicated Clemenceau's 1919 prediction that Versailles was "an armistice for twenty years" — the flawed peace settlement created the conditions Hitler exploited.
- → Topic 31 (Munich Agreement): The Nazi-Soviet Pact was a direct consequence of Munich — Stalin, excluded from the conference and seeing Britain concede without consulting him, concluded he needed to protect the USSR independently, making his deal with Hitler rational.
- → Topic 30 (Appeasement): War broke out because appeasement failed — Hitler's invasion of Poland proved the policy had not satisfied his aims but had instead enabled him to build the military strength to pursue Lebensraum without fear of an early response.
- → Topic 23 (League Structure): The League played no role in preventing war in September 1939 — its structural collapse meant the crisis was handled through bilateral guarantees (Britain to Poland) rather than collective security, illustrating how completely it had failed.
- → Topic 28 (Hitler's Foreign Policy): The invasion of Poland was the final stage of the VGL progression — Versailles reversed, Grossdeutschland achieved, and now Lebensraum beginning — all three aims from Mein Kampf (1925) being executed on schedule.