The Nazi-Soviet Pact and the Outbreak of World War Two
The Nazi-Soviet Pact and the Outbreak of World War Two
The period between March and September 1939 saw the final collapse of European peace. Hitler's invasion of Poland on 1 September 1939 triggered declarations of war by Britain and France on 3 September 1939, beginning the Second World War.
The Nazi-Soviet Pact (23 August 1939)
The most shocking diplomatic event of 1939 was the Nazi-Soviet Non-Aggression Pact (also called the Molotov-Ribbentrop Pact), signed on 23 August 1939 between Nazi Germany and the Communist Soviet Union — two regimes that were ideological enemies.
Terms of the Pact
- Public terms: Germany and the USSR agreed not to attack each other for ten years.
- Secret protocol: They agreed to divide Poland between them. The USSR would also take the Baltic states (Latvia, Lithuania, Estonia), Finland, and part of Romania.
Why Did Hitler Sign?
- He wanted to invade Poland without the risk of fighting the USSR at the same time (avoiding a two-front war).
- He believed Britain and France would back down once again if the USSR was no longer a potential ally for them.
- He could deal with the USSR later — he always intended to invade it for Lebensraum.
Why Did Stalin Sign?
- Distrust of Britain and France — Stalin had been excluded from the Munich Conference (1938). He believed the Western powers were trying to direct Hitler eastwards, towards the USSR.
- Time to prepare — The Soviet military had been weakened by Stalin's purges of army officers (1937-38). The pact bought time to rebuild.
- Territorial gains — The secret protocol gave the USSR a buffer zone of territory in Eastern Europe.
- Anglo-Soviet negotiations had failed — In the summer of 1939, Britain and France sent a low-ranking delegation (by sea, not air) to Moscow to discuss an alliance. Stalin concluded they were not serious.
The Invasion of Poland
- 1 September 1939 — German forces invaded Poland using Blitzkrieg ("lightning war") tactics: fast-moving tanks (Panzers), motorised infantry, and dive-bombers (Stukas) working together.
- 17 September 1939 — The Soviet Union invaded Poland from the east, as agreed in the secret protocol.
- Poland was overwhelmed. Warsaw surrendered on 27 September.
- Britain and France declared war on Germany on 3 September 1939, honouring their guarantee to Poland. However, they could not provide military assistance to Poland — it was too far away.
Causes of World War Two — Summary
The causes of WWII are complex and interconnected. Key factors include:
Long-term Causes
- The Treaty of Versailles created resentment in Germany and left unresolved tensions across Europe
- The failure of the League of Nations showed that collective security did not work
- The Great Depression caused economic misery, which helped extremists like Hitler gain power
Medium-term Causes
- Hitler's foreign policy aims — rearmament, Anschluss, Lebensraum
- Appeasement by Britain and France — gave Hitler time and territory without consequences
- The failure of disarmament — nations rearmed instead of reducing weapons
Short-term (Immediate) Causes
- The Nazi-Soviet Pact — removed the threat of a two-front war and made invasion of Poland possible
- The invasion of Poland (1 September 1939) — the direct trigger for war
- Britain and France's guarantee to Poland — meant they had to declare war
Debate: Who Was Most Responsible?
| Argument | Detail |
|---|---|
| Hitler | Deliberately pursued aggressive expansion; war was central to his ideology |
| Appeasers (Chamberlain) | Gave in to Hitler, encouraging further aggression; failed to stand firm early enough |
| The Treaty of Versailles | Created the conditions for resentment and extremism |
| Stalin | The Nazi-Soviet Pact made the invasion of Poland possible |
| The League of Nations | Failed to maintain collective security |
Key Exam Points
- The Nazi-Soviet Pact is often a source question topic — be prepared to analyse what it meant and why each side signed it.
- Know the chain of events from March 1939 (seizure of Czechoslovakia) to September 1939 (outbreak of war).
- For any "causes of WWII" question, discuss multiple factors and evaluate which was most important. The best answers consider long-term, medium-term, and short-term causes.