The Two World Wars and the Peace Settlements: Your Ultimate Study Guide!

Hello everyone! Welcome to your study notes for one of the most important topics in 20th-century history. We're going to explore the two biggest wars in human history – World War I and World War II. But we won't just focus on the fighting. More importantly, we'll look at what happened after the guns fell silent. How did the world try to build peace? And how did the attempt to fix things after WWI actually lead to WWII?

Understanding this chapter is super important because the decisions made in the 1920s and 1940s shaped the world we live in today, from the creation of the United Nations to the conflicts that still exist. Don't worry if it seems like a lot – we'll break it all down into simple, easy-to-understand parts. Let's get started!


Part 1: Cleaning Up the Mess of WWI - The Paris Peace Conference

The End of the "Great War"

When World War I ended in 1918, Europe was in ruins. Millions were dead, empires had collapsed, and countries were bankrupt. The winners – mainly France, Britain, and the USA – gathered in Paris in 1919 to decide the terms of peace and redraw the map of Europe. This was the Paris Peace Conference.

The Treaty of Versailles (1919)

This was the main peace treaty, specifically the one that dealt with Germany. The leaders of the "Big Three" countries had very different goals:

  • USA (President Wilson): Wanted a fair "peace without victory" and created a League of Nations to prevent future wars. He was an idealist.
  • France (Prime Minister Clemenceau): Wanted to crush Germany to make sure it could never attack France again. He wanted revenge!
  • Britain (Prime Minister Lloyd George): Was somewhere in the middle. He wanted to punish Germany, but not so harshly that it would cause another war.

In the end, France's desire for revenge largely won out. The terms of the Treaty of Versailles were very harsh on Germany. A great way to remember the main terms is with the mnemonic B.R.A.T.

Memory Aid: The Terms of the Treaty of Versailles = B.R.A.T.

B - Blame: Germany was forced to accept full blame for starting the war. This was called the 'War Guilt Clause' (Article 231). Imagine being blamed for a huge fight that everyone was involved in. This was deeply humiliating for the German people.

R - Reparations: Germany had to pay massive sums of money to the Allies for war damages (around £6.6 billion, a staggering amount back then). This crippled the German economy for years.

A - Army: Germany's military was severely restricted. Its army was limited to just 100,000 men, it was forbidden from having an air force or submarines, and the Rhineland (a key industrial area bordering France) was demilitarised.

T - Territory: Germany lost all its overseas colonies and about 13% of its land in Europe. This included important industrial regions like Alsace-Lorraine (returned to France) and areas given to the newly created Poland.

Impact on the International Order

The Paris Peace Conference didn't just punish Germany; it redrew the map of Europe. The old Austro-Hungarian and Ottoman Empires were broken up, creating new countries like Poland, Czechoslovakia, and Yugoslavia. The main impact was:

  • Widespread Resentment: The Treaty of Versailles created deep anger and resentment in Germany. This feeling of unfair punishment would later be exploited by leaders like Adolf Hitler.
  • A Weak Foundation for Peace: The treaty punished the losers but didn't solve the underlying problems that caused the war in the first place.
Key Takeaway for Part 1

The peace settlement after WWI, especially the Treaty of Versailles, was intended to prevent future wars but instead planted the seeds for the next one. By harshly punishing and humiliating Germany, it created the perfect conditions for extremist leaders to rise to power.


Part 2: The Inter-War Years (1919-1939) - A Failed Quest for Peace

The Big Idea: Collective Security

After the horror of WWI, people wanted to make sure it never happened again. President Wilson's big idea was collective security.

Analogy: Think of collective security like a neighbourhood watch for countries. If a bully (an aggressor country) attacks one house (country), all the other neighbours (member countries) promise to team up and stop the bully together. It's an "all for one, and one for all" approach to peace.

The organisation created to achieve this was the League of Nations.

The League of Nations: A Noble Failure

The League's main goal was to solve disputes between countries peacefully. Unfortunately, it was weak from the very beginning. Think of it as a watchdog with no teeth.

Why was the League so weak?
  • Membership Problems: The USA never joined! This was a huge blow, as America was the world's most powerful nation. Germany and the USSR were initially banned. Other key members like Japan and Italy left when the League criticised their actions.
  • No Army: The League had no army of its own. It could only ask its members to act, but it couldn't force them.
  • Slow Decisions: Decisions had to be unanimous, meaning one country could stop any action.

The Cause-and-Effect Chain: From WWI to WWII

The failures of the peace settlement and the League of Nations created a direct path to World War II. Here's how it happened, step-by-step:

1. Harsh Treaty of Versailles
leads to...
2. German Anger & Economic Collapse
leads to...
3. Rise of Hitler (who promises to destroy the Treaty and restore German pride)
is not stopped by the...
4. Weak League of Nations (which fails to act against Hitler's aggression in the 1930s)
which finally leads to...
5. The Outbreak of World War II in 1939.

Did you know?

A French military commander, Marshal Foch, said of the Treaty of Versailles in 1919: "This is not peace. It is an armistice for twenty years." He was almost exactly right – WWII began 20 years and 65 days later.

Key Takeaway for Part 2

The attempts at collective security in the inter-war period failed. The League of Nations was too weak to stop aggressive countries. This failure, combined with the resentment from the Treaty of Versailles, made a second world war almost inevitable.


Part 3: The End of WWII & A New World Order

The Post-WWII Settlements

After WWII ended in 1945, the Allies learned from the mistakes of 1919. Instead of one big, messy conference, the leaders met several times during the war to plan for the post-war world. The most important meetings were the Yalta and Potsdam Conferences (1945).

The new "Big Three" were the USA, the USSR (Soviet Union), and Britain. Their key decisions shaped the next 50 years:

  • Dividing Germany: They agreed to divide Germany – and its capital, Berlin – into four occupation zones, controlled by the USA, USSR, Britain, and France. This division would eventually become West and East Germany.
  • Creating the United Nations: They all agreed to create a new, stronger international organisation to replace the failed League of Nations.
  • The Iron Curtain: At these conferences, deep disagreements emerged between the USA (capitalist) and the USSR (communist). The Soviet Union refused to remove its troops from the Eastern European countries it had liberated from the Nazis, setting the stage for a divided Europe.

Impact: A New International Order

The end of WWII completely changed the world's power structure.

1. The Rise of Two Superpowers: The old powers of Britain and France were exhausted. The world was now dominated by two new superpowers with opposing ideologies: the democratic, capitalist USA and the communist USSR.

2. The Beginning of the Cold War: The deep mistrust between the USA and USSR led to the Cold War – a 45-year period of tension and rivalry that divided the world into two camps. There was no direct fighting between the two, but many proxy wars.

3. The United Nations (UN): The UN was established in 1945. It was designed to be stronger than the League. A key difference is the Security Council, which has the power to authorise military action. It has 5 permanent members (USA, Russia, China, UK, France) who can veto any decision.

Key Takeaway for Part 3

The post-WWII settlements did not repeat the mistake of a single punitive treaty like Versailles. Instead, they established a new international order dominated by two rival superpowers (USA and USSR), leading to the Cold War. A new and improved body for collective security, the United Nations, was also created.


Part 4: The Big Picture: Overall Significance of the World Wars

How did these two massive conflicts change the world forever? We can assess their historical significance from four perspectives. A good way to remember this is P.S.E.C. (Political, Social, Economic, Cultural).

Political Significance

  • End of Empires: The wars destroyed Europe's old empires. WWI ended the Russian, Ottoman, and Austro-Hungarian empires. WWII fatally weakened the British and French colonial empires, leading to decolonisation across Asia and Africa.
  • Shift in Global Power: Power shifted away from Western Europe to the USA and the USSR.
  • New International Bodies: The wars led to the creation of the League of Nations and, more successfully, the United Nations.

Social Significance

  • Unprecedented Loss of Life: The scale of death was immense, especially among civilians in WWII.
  • Changed Role of Women: With men away fighting, women entered the workforce in huge numbers, which helped advance the cause of women's rights and suffrage (the right to vote).
  • Mass Migration: Millions of people were displaced from their homes, becoming refugees.

Economic Significance

  • European Destruction: Much of Europe was physically and economically destroyed after both wars.
  • Rise of the USA: The USA emerged from both wars as the world's leading economic power.
  • Increased Government Role: Governments took on a much larger role in managing their national economies.

Cultural Significance

  • Disillusionment: The horror of WWI trench warfare led to a "Lost Generation" of artists and writers who were deeply cynical and pessimistic about the world.
  • The Nuclear Age: The use of atomic bombs on Japan at the end of WWII ushered in the nuclear age and the constant fear of atomic warfare during the Cold War.
  • Human Rights Awareness: The world's horrified reaction to the Holocaust led to new ideas about universal human rights and the prosecution of war crimes (e.g., the Nuremberg Trials).
Final Takeaway

The two world wars were a turning point in human history. They ended an era of European dominance, created a new global power structure dominated by the USA and USSR, and led to the creation of new international systems aimed at preventing such a catastrophe from ever happening again. Their political, social, economic, and cultural consequences are still felt all over the world today.