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European diplomacy and the outbreak of war in 1939

A long chain of events invites a simple answer, and the evidence rarely supports one.

On this page
  1. What happened, in order?
  2. How have people explained these events?
  3. Worked example: a qualified causal paragraph
  4. What mistake do students make?
  5. Check yourself
  6. Where this leads next

In the three years before September 1939, a series of German actions and diplomatic responses shaped the road to war. The documented events are clear. What caused them to unfold as they did is a matter of interpretation, and that is where marks are won.

This lesson is part of Core option B study pathways and follows the League of Nations unit.

What happened, in order?

  • March 1936: German troops enter the demilitarised Rhineland. Britain and France protest but do not act militarily.
  • March 1938: Anschluss, the union of Germany and Austria.
  • September 1938: the Munich Agreement, signed by Britain, France, Germany and Italy, transfers the Sudetenland from Czechoslovakia to Germany. Czechoslovak representatives were not at the table.
  • 15 March 1939: German forces occupy the rest of the Czech lands.
  • 31 March 1939: Britain, with France, gives a formal commitment to support Poland.
  • 23 August 1939: the Nazi-Soviet Pact is signed.
  • 1 September 1939: German forces invade Poland. On 3 September Britain and France declare war on Germany.

How have people explained these events?

  • Contemporary supporters of appeasement: argued that the policy avoided war, that Germany had some legitimate grievances and that Britain was not yet ready to fight. Those claims are viewpoints from the time.
  • Contemporary critics: argued that concessions encouraged further demands.
  • A. J. P. Taylor (1961): argued that Hitler exploited opportunities as they arose rather than following a fixed timetable.
  • Other historians: argue that Hitler pursued longer-term aims that were consistent from the 1920s.

These are attributed interpretations. A good answer neither adopts one nor lists them without comment.

Worked example: a qualified causal paragraph

Question: How far did the Munich Agreement make war in 1939 more likely?

“The Munich Agreement may have made war more likely because it transferred the Sudetenland to Germany without Czechoslovak participation, and in March 1939 German forces occupied the remaining Czech lands, which showed that Germany did not stop at the Munich terms. However, the agreement also delayed conflict by about a year, and defenders of the policy argued that this gave Britain time to rearm. The evidence therefore supports Munich as one contributing factor, not the sole cause. The commitment to Poland and the Nazi-Soviet Pact are other developments that shaped how the crisis of August 1939 unfolded.”

Note the qualifiers (“may”, “however”, “one contributing factor”) and the attributed argument.

What mistake do students make?

Mistaken answer: “Munich caused the war because Chamberlain was weak.”

“Weak” is a judgement and the answer gives no evidence. Add the documented sequence and the arguments of both defenders and critics, and then give your own supported conclusion.

Check yourself

1. Put in order: Nazi-Soviet Pact, Anschluss, Munich Agreement, invasion of Poland.

Show answer

Anschluss (March 1938), Munich Agreement (September 1938), Nazi-Soviet Pact (23 August 1939), invasion of Poland (1 September 1939).

2. Who argued that Hitler exploited opportunities rather than following a fixed timetable?

Show answer

A. J. P. Taylor, in his 1961 book, as an interpretation that other historians challenged.

3. Why is “Britain should have fought in 1938” not a suitable sentence?

Show answer

It judges with hindsight and offers no evidence. A suitable alternative describes what British leaders aimed for in 1938 and what followed.

Where this leads next

Use the terms versus interpretations lesson to check your wording, then continue to Cold War origins. The practice set includes a causation question. For individual feedback on causal paragraphs, see our online one-to-one History tuition.

Questions people ask

Was the outbreak of war in 1939 caused by appeasement?

Appeasement is one factor that historians discuss, among others, such as German aims, the Nazi-Soviet Pact and the Anglo-French commitment to Poland. How much weight each deserves is an interpretation. A strong answer states the evidence for each factor and then explains its own ranking.

Do I need to know the secret protocol of the Nazi-Soviet Pact?

Check your syllabus and class notes. The pact was signed on 23 August 1939, and a secret protocol dividing influence in Eastern Europe was documented later. Be clear about what was publicly known in 1939 and what came out afterwards.

What is the difference between a cause and a trigger?

A cause helps explain why war was likely. A trigger is the event that set it off. The invasion of Poland on 1 September 1939 is usually discussed as the trigger, while causes lie in earlier developments. Use the terms carefully and give evidence.

Sources

  1. Cambridge IGCSE History 0470 subject page

Updated:

Your next step

If your 1939 answers list events without weighing them, a one-to-one teacher can practise ranking and linking causes with you, using your own essays.

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