Core Content: Option B
International Relations Since 1919

1. The Peace Treaties of 1919–1920

The settlement following the First World War was negotiated at the Paris Peace Conference. The final treaties represented a series of uneasy compromises among the "Big Three" leaders, whose geopolitical objectives varied significantly based on their domestic political constraints and structural losses during the conflict.

1.1 Conflicting Motives of the Big Three

• Georges Clemenceau (France): Driven by deep security concerns and a desire for geopolitical retribution. France had suffered immense casualties and industrial devastation. Clemenceau demanded the severe military disarmament of Germany, substantial financial reparations to fund reconstruction, the permanent demilitarization of the Rhineland as a buffer zone, and the return of Alsace-Lorraine.
• Woodrow Wilson (USA): Approached the negotiations from an idealistic standpoint, framed around his Fourteen Points. Wilson advocated for the establishment of national self-determination to eliminate imperial friction points, global maritime free trade, general disarmament, and the creation of a League of Nations to guarantee collective security and prevent future secret diplomatic alliances.
• David Lloyd George (Great Britain): Occupied a pragmatic middle ground. Publicly, he was bound by anti-German electoral rhetoric ("Hang the Kaiser"). Privately, he sought to maintain Britain's naval supremacy and preserve the British Empire. He opposed crushing Germany economically, recognizing that a stable Germany was essential as a trading partner and served as a vital geopolitical bulwark against the spread of Bolshevism from Soviet Russia.

1.2 Terms of the Treaty of Versailles (Germany)

1.3 The Other Paris Peace Settlements

The collapse of the multi-ethnic empires of Central and Eastern Europe necessitated parallel settlements for Germany's wartime allies:

• Treaty of Saint-Germain (1919) - Austria: Formally dissolved the Austro-Hungarian Empire. Displaced vast territories to create new nation-states (Czechoslovakia, Yugoslavia, and an expanded Poland). Conscription was banned, and army limits were capped at 30,000 men.
• Treaty of Neuilly (1919) - Bulgaria: Ceded Western Thrace to Greece, cutting off Bulgaria's direct access to the Aegean Sea. Re-allocated Dobruja to Romania. Reparations fixed at £100 million, with military capacity restricted to 20,000 soldiers.
• Treaty of Trianon (1920) - Hungary: Deprived Hungary of over two-thirds of its historic pre-war territory. Transferred Transylvania to Romania, and Slovakia to Czechoslovakia. Over three million ethnic Hungarians were left outside the state's new borders. Military restricted to 35,000 men.
• Treaty of Sèvres (1920) & Lausanne (1923) - Ottoman Empire: Sèvres stripped the Empire of its Arab territories and placed the Dardanelles Straits under international control. This sparked a nationalist uprising led by Mustafa Kemal, which forced the Allies to renegotiate terms via the Treaty of Lausanne. This returned East Thrace and Smyrna to Turkish sovereignty and removed independent financial reparations demands.

2. The League of Nations

The League of Nations was established to secure international peace through institutional collaboration. Its operational success was limited by deep structural vulnerabilities in its design and shifting economic realities across the globe.

2.1 Structural Design Failures and Weaknesses

• Absence of Major Powers: The United States Senate rejected ratification of the Treaty of Versailles, retreating into isolationism. This deprived the League of its primary financial and military backer. Soviet Russia was initially excluded due to ideological fears of communism, and Germany was barred until its entry in 1926. This left the League perceived as a selective "winners' club."
• Enforcement Limitations: The League possessed no standing military force of its own. It relied entirely on member states volunteering troops. Economic sanctions were frequently ineffective because non-member states (such as the US) could continue trading with targeted aggressors.
• Procedural Gridlock: The Assembly and Council required **unanimous votes** to pass major resolutions. This meant any single aggressive state could veto condemnation actions, paralyzing the organization during crises.

2.2 Successes and Failures in the 1920s

During its first decade, the League achieved notable humanitarian successes and successfully mediated secondary territorial border disputes:

• Aaland Islands (1921): Successfully settled ownership of the islands between Sweden and Finland. The League ruled in favor of Finnish sovereignty, and Sweden accepted the decision, averting conflict.
• Upper Silesia (1921): Partitioned an industrial border zone between Germany and Poland following a plebiscite. The division was accepted by both nations, ensuring an orderly transition.
• Bulgaria-Greece Border Dispute (1925): Imposed an immediate ceasefire after Greek troops crossed the Bulgarian border following a frontier skirmish. The League condemned the Greek invasion and ordered financial compensation, which Greece paid.
• Humanitarian Agencies: The International Labour Organization (ILO) successfully limited lead usage in manufacturing and campaigned for an eight-hour workday. The Refugee Commission resettled hundreds of thousands of displaced persons from the post-war displacement crises, and the Health Committee actively combated outbreaks of malaria and typhus.
• Core Failures (Corfu, 1923): Italian general Tellini was assassinated on Greek soil. Benito Mussolini retaliated by bombarding and occupying the Greek island of Corfu. Greece appealed to the League, but Mussolini pressured the Conference of Ambassadors behind the scenes. The League altered its initial rulings, forcing Greece to apologize and pay financial compensation directly to Italy, demonstrating that major powers could bypass League authority.

2.3 Collapse of the League in the 1930s

The onset of the Great Depression shattered international economic cooperation, leading to protectionist policies and emboldening aggressive nationalist regimes.

3. The Collapse of International Peace by 1939

The path to war in Europe was driven by the revisionist foreign policy of Adolf Hitler, alongside the failure of the international community to challenge aggressive actions early on.

3.1 Hitler's Foreign Policy Aims

1. Abolish the Treaty of Versailles: Reverse all territorial provisions, reclaim lost lands, and rebuild Germany's full military capacity.
2. Lebensraum (Living Space): Conquer agricultural and raw material resources in Eastern Europe and Soviet Russia to sustain the German nation.
3. Grossdeutschland (Greater Germany): Unite all German-speaking populations scattered across Europe into a single nation-state (including Austria, the Sudetenland, and the Polish Corridor).
4. Destruction of Communism: Eradicate the Soviet state and eliminate the threat of Bolshevism.

3.2 Chronology of Aggression and Appeasement

• Rearmament & The Saar Plebiscite (1935): Hitler publicly announced Germany's rearmament program and re-introduced conscription, directly violating the Treaty of Versailles. The Saar region voted overwhelmingly (over 90%) in a League-supervised plebiscite to rejoin Germany, boosting the regime's domestic popularity.
• Remilitarization of the Rhineland (1936): Hitler marched 22,000 troops into the demilitarized Rhineland, a major calculated gamble. France was paralyzed by a domestic political crisis, and Britain viewed the move as Germany merely re-occupying "its own backyard." No international intervention occurred.
• Anschluss with Austria (1938): Hitler pressured Austrian Chancellor Schuschnigg into accepting German dominance, eventually sending troops into the country to secure a unified state. The union was confirmed by a managed plebiscite. Britain and France offered diplomatic protests but took no concrete action.
• The Munich Agreement & Sudetenland Crisis (1938): Hitler demanded the secession of the German-populated Sudetenland from Czechoslovakia. British Prime Minister Neville Chamberlain pursued a policy of **Appeasement**, seeking to prevent war through negotiation. At the Munich Conference (excluding Czechoslovakia and the USSR), Britain and France agreed to permit Germany's annexation of the Sudetenland in exchange for a promise of no further territorial expansion. By March 1939, Hitler broke this agreement, invading and occupying the rest of the Czech state.
• The Nazi-Soviet Pact (August 1939): A non-aggression pact signed between Nazi Germany and the Soviet Union. Secret clauses partitioned Poland between them and allowed the USSR to secure influence in the Baltic states. This agreement freed Germany from the threat of a two-front war, clearing the way for the invasion of Poland on September 1, 1939, which prompted Britain and France to declare war.

4. The Cold War: Ideology and Polarization

Following the defeat of the Axis powers, the wartime alliance between the United States and the Soviet Union dissolved into a global ideological conflict between capitalism and communism.

4.1 Wartime Conferences: Yalta and Potsdam (1945)

The geopolitical divisions of post-war Europe emerged during negotiations held before the conflict concluded:

• Yalta Conference (February 1945): Held while the war was active. The leaders agreed to divide Germany and Berlin into four occupation zones. They committed to permitting free elections across liberated Europe and confirmed Soviet entry into the war against Japan. Stalin demanded a sphere of influence in Eastern Europe, promising to allow democratic representation in Poland.
• Potsdam Conference (July-August 1945): Held after Germany's surrender. The political landscape had shifted: President Roosevelt had died and was replaced by Harry Truman (who adopted a significantly firmer stance against communism), and Winston Churchill was replaced mid-conference by Clement Attlee. Truman revealed the successful testing of the atomic bomb, raising tensions with Stalin. Disputes arose over the exact adjustments to Poland's borders and the volume of industrial reparations Stalin could extract from the Western occupation zones.

4.2 The US Policy of Containment

In response to the establishment of pro-Soviet communist governments across Eastern Europe (the "Iron Curtain"), the United States developed a strategy of containment to block the spread of Soviet influence:

• The Truman Doctrine (1947): A commitment that the United States would provide financial and military aid to any nation resisting armed minorities or external communist pressure, initially applied to support Greece and Turkey during their post-war crises.
• The Marshall Plan (1947–1948): A massive economic aid package directing over $13 billion into rebuilding Western Europe's shattered economies. The US recognized that economic stability was an effective defense against the political appeal of communism. Stalin banned Eastern European states from accepting the funds, launching Comecon and Cominform to coordinate economic and political policy across the Soviet bloc.
• The Berlin Blockade and Airlift (1948–1949): In response to the introduction of a new currency (the Deutsche Mark) in the Western occupation zones, Stalin cut off all surface transit routes linking West Berlin to West Germany, aiming to force the Western allies to abandon the city. The West responded with the Berlin Airlift, flying over 200,000 flights to deliver food, coal, and supplies for eleven months. Stalin lifted the blockade in May 1949, and the crisis accelerated the formal creation of West Germany (FRG), East Germany (GDR), and the NATO military alliance.

5. Cold War Containment in Action: America Confronts Communism

As containment solidified in Europe, the conflict expanded into dynamic regional confrontations across Asia and the Americas.

5.1 The Korean War (1950–1953)

Following the partition of Korea along the 38th Parallel after World War II, communist North Korea launched an invasion of capitalist South Korea in June 1950. The United States secured a United Nations resolution to intervene militarily, taking advantage of a Soviet boycott of the UN Security Council at the time.

• Course of the Conflict: UN forces, led by General Douglas MacArthur, were initially pushed back to the Pusan Perimeter. MacArthur executed a counter-offensive landing at Inchon, driving North Lankan forces back across the border and advancing toward the Yalu River. Alarmed by this advance, Communist China entered the war, deploying hundreds of thousands of troops to push UN forces back southward.
• Resolution and Outcome: The conflict settled into a war of attrition along the 38th Parallel. An armistice was signed in 1953, establishing a permanent Demilitarized Zone (DMZ). The war demonstrated the US commitment to containment in Asia but underscored the risks of direct confrontation with regional communist powers.

5.2 The Cuban Missile Crisis (1962)

In 1959, Fidel Castro overthrew the Batista regime in Cuba, establishing a communist government aligned with the Soviet Union. The US attempted to overthrow Castro via the failed **Bay of Pigs invasion** in 1961, pushing Cuba to seek direct military protection from Moscow.

• The Thirteen Days (October 1962): US U-2 spy planes photographed Soviet nuclear missile launch sites under construction in Cuba. President John F. Kennedy rejected demands for an immediate air strike, choosing to establish a naval "quarantine" (blockade) around Cuba to intercept Soviet supply vessels.
• Resolution Mechanics: Following direct messaging between Kennedy and Khrushchev, a public compromise was reached: the Soviet Union agreed to dismantle and remove all offensive weapons from Cuba under UN supervision, in exchange for a public US pledge not to invade the island. Secretly, the US also agreed to remove its older Jupiter nuclear missiles from Turkey. The crisis led to the installation of a direct hot-line between Washington and Moscow and accelerated the signing of the Limited Test Ban Treaty.

5.3 The Vietnam War

The US intervention in Vietnam was driven by the **Domino Theory**—the belief that if one nation fell to communism, surrounding countries would inevitably follow. Following the defeat of French colonial forces in 1954, Vietnam was partitioned along the 17th Parallel into a communist North (led by Ho Chi Minh) and a capitalist South (led by Ngo Dinh Diem).

• Military Challenges: US forces struggled against the guerrilla warfare tactics used by the National Liberation Front (Viet Cong) and North Vietnamese Army. The Viet Cong utilized the Ho Chi Minh trail for logistics and avoided conventional battles, rendering traditional US technological superiority less effective. Tactics like Operation Rolling Thunder, Search and Destroy missions, and the deployment of chemical agents (Agent Orange, Napalm) caused significant civilian casualties, eroding local support.
• Domestic Opposition and Withdrawal: The **Tet Offensive** in 1968 shattered public assertions that the war was being won. Growing domestic anti-war protests, economic strain, and rising military casualties forced President Richard Nixon to implement "Vietnamization"—gradually withdrawing US ground forces while shifting combat responsibilities onto the South Vietnamese army. US forces withdrew completely following the Paris Peace Accords, and in 1975, North Vietnamese forces captured Saigon, unifying the country under communist rule.

6. Soviet Control Over Eastern Europe

Between 1956 and 1980, the Soviet Union repeatedly deployed military force to preserve its ideological and strategic control over its satellite states in Eastern Europe.

6.1 The Hungarian Uprising (1956)

• Causes: Widespread public anger over food shortages, secret police terror, and political repression under the hardline Stalinist regime of Mátyás Rákosi. Inspired by Nikita Khrushchev’s "Secret Speech," which criticized Stalin's methods, reformist leader Imre Nagy was brought to power.
• Nagy's Reform Program: Nagy proposed ending the one-party state, releasing political prisoners, and introducing free speech. The critical line was crossed when he announced plans for Hungary to **withdraw from the Warsaw Pact** and declare neutrality.
• Soviet Suppression: Alarmed by the threat to the unity of the Soviet bloc, Khrushchev ordered 200,000 Soviet troops and thousands of tanks into Budapest. The uprising was suppressed, resulting in over 2,500 Hungarian casualties. Nagy was arrested and executed, and Janos Kadar was installed to restore strict Soviet alignment.

6.2 The Prague Spring (1968)

• Causes: Alexander Dubček became leader of the Communist Party in Czechoslovakia, launching a reform movement aimed at delivering "Socialism with a human face."
• Dubček's Reforms: Introduced the abolition of press censorship, expanded consumer goods production, granted greater freedom of movement, and permitted public criticism of government actions. Crucially, Dubček repeatedly stated that Czechoslovakia had **no intention** of leaving the Warsaw Pact or abandoning communism.
• Soviet Suppression: Soviet leader Leonid Brezhnev feared these reforms would spread to other satellite states. Warsaw Pact forces launched an invasion of Czechoslovakia, arresting Dubček and rolling back the reforms. This action was justified by the **Brezhnev Doctrine**, which asserted that the USSR reserved the right to intervene in any socialist nation where communist rule was deemed under threat.

6.3 The Collapse of Soviet Control

The system collapsed rapidly in the late 1980s due to structural economic stagnation and new reform initiatives introduced by Mikhail Gorbachev:

• Gorbachev's Reforms: Introduced *Glasnost* (Political Openness) and *Perestroika* (Economic Restructuring) to modernize the struggling Soviet economy. Crucially, Gorbachev abandoned the Brezhnev Doctrine, stating that the USSR would no longer deploy military force to support communist regimes in Eastern Europe.
• The Collapse: This policy change triggered a wave of peaceful revolutions across Eastern Europe. Border controls were dismantled, leading to the fall of the **Berlin Wall** in November 1989. Within two years, communist regimes fell across the region, culminating in the formal dissolution of the Soviet Union in December 1991.