Key facts and dates

The year 1939 marked a critical turning point in global history, as a series of diplomatic failures, aggressive actions, and miscalculations led to the outbreak of the Second World War. The following timeline captures the pivotal events that escalated tensions and resulted in widespread conflict.

Timeline of key events

• 31 March 1939 – Britain and France issue a guarantee to protect Poland against aggression.
• April-May 1939 – Britain and France extend guarantees to Romania (April 13), Greece (April 13), and Turkey (May 12).
• April-August 1939 – Anglo-French-Soviet negotiations fail to form a united front against Germany.
• 23 August 1939 – Nazi-Soviet Pact signed, shocking the world with a non-aggression agreement and secret territorial divisions.
• 1 September 1939 – Hitler invades Poland, triggering the start of the Second World War.
• 3 September 1939 – Britain and France declare war on Germany after issuing ultimatums.

The post-Munich situation and the end of appeasement

Following the Munich Agreement of 1938, which allowed Germany to annex the Sudetenland from Czechoslovakia, the policy of appeasement—conceding to Hitler's demands to avoid conflict—began to unravel. By early 1939, it became clear that further concessions would not satisfy Nazi ambitions, prompting a shift in British and French strategies.

Key developments after Munich

• Loss of faith in appeasement - The Munich Agreement failed to secure lasting peace, as Hitler's subsequent occupation of the rest of Czechoslovakia in March 1939 demonstrated his disregard for diplomatic agreements.
• Guarantees to Eastern Europe - In response, Britain and France pledged military support to Poland in March 1939, followed by guarantees to Romania, Greece, and Turkey in April-May 1939, aiming to deter further German aggression by showing a united front.
• Acceleration of rearmament - Both nations ramped up military production and preparedness, recognising that war might be inevitable if Hitler continued his expansionist policies.
• Shift in policy - This marked the end of appeasement, as leaders like British Prime Minister Neville Chamberlain realised that further compromise would only embolden Hitler, necessitating a firmer stance.

Hitler's aims and actions regarding Poland

Adolf Hitler had specific territorial and ideological goals in Eastern Europe, with Poland as a central target. His demands were rooted in reversing the Treaty of Versailles (1919), which he viewed as a humiliating imposition on Germany.

Hitler's objectives in Poland

• Return of Danzig - Hitler demanded the return of the city of Danzig (modern-day Gdańsk), a predominantly German-speaking free city under League of Nations protection since Versailles, to German sovereignty.
• Extraterritorial access to East Prussia - He sought a corridor through Polish territory to connect mainland Germany with East Prussia, which was geographically isolated by the Polish Corridor established post-1919.
• Destruction of Versailles settlement - Beyond specific territorial gains, Hitler aimed to dismantle the entire Versailles framework in Eastern Europe, viewing it as an obstacle to German dominance and a source of national shame.
• Aggressive intent - These demands were not merely diplomatic; they were backed by a willingness to use military force, reflecting Hitler's broader goal of territorial expansion and Lebensraum (living space) for the German people.

The failure of Anglo-French-Soviet negotiations

Between April and August 1939, Britain and France attempted to forge an alliance with the Soviet Union to counter German aggression. These negotiations, however, were plagued by deep mistrust and conflicting interests, ultimately collapsing and leaving a critical gap in the anti-Hitler coalition.

Reasons for the breakdown of talks

• Mutual suspicions - The Soviets feared betrayal by the West, recalling how appeasement had sacrificed Czechoslovakia; meanwhile, Britain and France were wary of aligning with a communist state due to ideological opposition to Bolshevism.
• Polish resistance - Poland, fearing Soviet domination, refused to allow Soviet troops to pass through its territory in the event of a conflict, severely limiting the practicality of a military alliance.
• Lack of commitment - British and French delegations were slow and appeared less urgent, underestimating Soviet concerns, while Stalin grew frustrated with the lack of concrete guarantees against Germany.
• Ultimate failure - Without a unified front, the negotiations ended without agreement, leaving the door open for alternative alliances and weakening the position of those opposing Hitler.

The significance of the Nazi-Soviet Pact

On 23 August 1939, the world was stunned by the signing of the Nazi-Soviet Pact, a non-aggression treaty between Germany and the Soviet Union. This unexpected alliance reshaped the geopolitical landscape and paved the way for immediate conflict.

Key aspects of the pact

• Shock to the international community - The agreement between two ideologically opposed regimes—Nazi Germany and Communist Soviet Union—was unforeseen, shattering hopes of a united anti-German front.
• Secret protocol - A hidden clause divided Eastern Europe into spheres of influence, with Germany gaining control over western Poland and the Soviets taking eastern Poland, the Baltic states, and parts of Romania, effectively partitioning the region.
• Stalin's calculations - Soviet leader Joseph Stalin believed the pact would buy time to strengthen his military and avoid immediate conflict, while also securing territorial gains without fighting.
• Strategic advantage for Hitler - The pact eliminated the threat of a two-front war for Germany, as Soviet neutrality meant Hitler could focus on Western Europe without fear of eastern intervention.

The invasion of Poland and the declarations of war

With diplomatic avenues exhausted and the Nazi-Soviet Pact securing his eastern flank, Hitler moved swiftly against Poland. This act of aggression directly triggered the start of the Second World War.

Sequence of events in early September 1939

1. Invasion on 1 September 1939 - German forces launched a full-scale invasion of Poland, employing blitzkrieg tactics (rapid, coordinated attacks using tanks and air power) to overwhelm Polish defences.
2. Last-minute diplomatic efforts - Frantic attempts by Britain and France to negotiate a peaceful resolution failed, as Hitler remained committed to military action.
3. Ultimatums issued - Britain and France delivered ultimatums to Germany, demanding withdrawal from Poland, but these were ignored, reflecting Hitler's belief that the Allies would not fight, as they had not over Czechoslovakia.
4. Declarations of war on 3 September 1939 - With no German retreat, Britain and France formally declared war on Germany, marking the official start of the Second World War in Europe.

Hitler's miscalculations

• Underestimation of Allied resolve - Hitler assumed Britain and France would back down over Poland as they had over Czechoslovakia, misjudging their newfound determination to resist.
• Confidence in military superiority - He believed Germany's rearmed forces could quickly crush Poland and deter Western intervention through sheer strength.
• Impact of Soviet neutrality - The Nazi-Soviet Pact bolstered his confidence by removing the risk of fighting on two fronts, allowing him to focus resources on Poland.

Reasons for the outbreak of war in 1939

The eruption of war in September 1939 was the culmination of multiple interconnected factors, ranging from failed diplomacy to aggressive expansionism. Understanding why conflict became inevitable requires examining both immediate triggers and broader underlying causes.

Why war broke out in 1939

• Failure of appeasement - The policy of conceding to Hitler's demands, intended to preserve peace, instead encouraged further aggression by failing to set firm boundaries, as seen in the Czech crisis.
• Hitler's unlimited ambitions - Hitler's goals extended far beyond territorial revisions; his vision of a German-dominated Europe left no room for compromise, making conflict almost certain.
• Impossibility of further concessions - After Munich and the occupation of Czechoslovakia, Britain and France recognised that yielding more territory, such as in Poland, would only weaken their position further.
• Allied determination - The guarantees to Poland reflected a clear line in the sand; Britain and France were now prepared to fight to uphold their credibility and halt Nazi expansion.
• Critical turning points - War might have been delayed if the Anglo-French-Soviet talks had succeeded or if the Nazi-Soviet Pact had not been signed, but by mid-1939, Hitler's actions and the breakdown of diplomacy made conflict unavoidable.
• Inevitable escalation - The invasion of Poland was the final trigger, but the deeper issue was the incompatibility between Hitler's expansionist ideology and the Allies' eventual resolve to resist, suggesting war was inevitable once appeasement was abandoned.