Paper 2: 20th-Century Wars — Effects of 20th-Century Wars

· Exact syllabus location: Paper 2: World history topic 11 — Causes and effects of 20th-century wars.
· Specified subtopic: Effects of war.
· Official syllabus focus: “The successes and failures of peacemaking”; “Territorial changes”; “Political impact: short-term and long-term”; “Economic, social and demographic impact; changes in the role and status of women.”
· Main exam expectation: students must use specific 20th-century wars and may need examples from two different regions of the world.
· Important IB rule: syllabus examples are suggested only, not compulsory. However, essays must use precise wars, not general claims about “war”.
· Cross-regional warning: First World War, Second World War and Russo-Japanese War may be used in a regional context, but not twice in different regions in the same answer. For example, use Second World War in the Pacific, not both Second World War in Europe and Second World War in the Pacific as two separate regions.

What “effects of war” really means

· This subtopic is about judging how far war changed states, borders, societies, economies and populations after the fighting ended.
· Strong answers do not simply describe destruction; they explain which effects were short-term, which became long-term, and why some effects were more significant than others.
· The best essays connect effects to earlier syllabus areas: type of war, mobilization, foreign involvement, and technology often shaped the scale of political, economic, social and demographic consequences.
· A top-grade argument should compare effects across wars, for example: civil wars often produce regime change and social division, while wars between states often produce territorial settlements and peacemaking problems.

Peacemaking: successes and failures

· Peacemaking means the attempt to create a stable post-war settlement. IB essays should assess whether peace settlements solved the causes of conflict or created new tensions.
· First World War, 1914–1918, Europe: Treaty of Versailles, 1919 can be used as a major example of failed peacemaking because it formally ended war but left disputes over reparations, war guilt, disarmament, and territorial revisionism. Use it to argue that a settlement can be legally successful but politically unstable.
· Second World War, 1939–1945, Europe/Pacific: post-war settlements were more successful in defeating aggressive regimes, but created new tensions through occupation, division of Germany, and the emergence of the Cold War. Use this to show that peacemaking can solve one conflict while helping create another international rivalry.
· Vietnam War, 1964–1975, Asia and Oceania: the Paris Peace Accords, 1973 failed to create lasting peace in South Vietnam, as the war ended with the fall of Saigon, 1975 and communist victory. Use this as evidence that peacemaking without enforceable political compromise may collapse.
· Algerian War, 1954–1962, Africa and the Middle East: the Evian Accords, 1962 ended French colonial rule and brought Algerian independence. Use this as a more successful example of peacemaking in terms of ending colonial war, but evaluate the long-term instability caused by violence, displacement and post-war political dominance by the FLN.
· Spanish Civil War, 1936–1939, Europe: peacemaking was minimal because Franco’s Nationalists achieved military victory rather than negotiated settlement. Use this to argue that civil wars may end through victory and repression, not compromise.

Territorial changes

· Territorial changes are often the easiest effects to identify, but essays must explain their significance: did borders create stability, nationalism, resentment, partition, refugee movements or new states?
· First World War, Europe: the collapse of the German, Austro-Hungarian, Russian and Ottoman empires produced new or enlarged states, including Poland, Czechoslovakia and Yugoslavia. Use this to show that territorial change can be both a peace aim and a source of future ethnic and nationalist tension.
· Second World War, Europe: Germany was defeated, occupied and divided into zones, later contributing to the creation of East Germany and West Germany. Use this to argue that territorial outcomes can become long-term political structures.
· Second World War in the Pacific: Japan lost its empire, including control over territories gained through expansion. Use this to show how defeat can dismantle imperial systems and transform regional power balances.
· Indo-Pakistan War, 1971, Asia and Oceania: the war led to the creation of Bangladesh from East Pakistan. Use this as a clear example where war produced direct territorial and state-formation change.
· First Gulf War, 1990–1991, Africa and the Middle East: Iraq’s occupation of Kuwait was reversed, showing that war can preserve existing borders rather than redraw them. Use this as a contrast with wars that created new states.

Political impact: short-term and long-term

· Short-term political impact usually includes regime collapse, occupation, revolution, military victory, peace treaties, or power vacuums.
· Long-term political impact includes new governments, authoritarian rule, decolonization, partition, ideological realignment, or superpower involvement.
· Russian Civil War, 1917–1922, Europe: Bolshevik victory consolidated communist rule and led to the creation of the USSR. Use this to show how civil war can determine the ideological structure of a state for decades.
· Spanish Civil War, 1936–1939, Europe: Franco’s victory created a long-lasting authoritarian regime. Use this to argue that civil wars can produce decisive regime change and repression rather than reconciliation.
· Chinese Civil War, 1927–1937 and/or 1946–1949, Asia and Oceania: communist victory in 1949 produced the People’s Republic of China, while the Guomindang retreated to Taiwan. Use this as a high-value example of political transformation after civil war.
· Algerian War, 1954–1962, Africa and the Middle East: French withdrawal ended colonial rule and strengthened the FLN as the dominant political force in independent Algeria. Use this to connect war effects to decolonization and post-war state-building.
· Falklands/Malvinas War, 1982, Americas/Europe link: defeat weakened Argentina’s military junta and contributed to the return of civilian rule. Use this to show that even a short war can have major domestic political consequences.

Economic effects

· Economic effects should be judged by scale, duration, and who paid the cost: states, civilians, defeated powers, colonial populations or reconstruction agencies.
· First World War, Europe: massive war debt, reconstruction costs, inflation and reparations disputes weakened post-war economies. Use this to link economic effects to the failure of peacemaking and later political instability.
· Second World War, Europe/Japan: destruction of infrastructure and industry was severe, but post-war reconstruction reshaped economies through occupation policies and rebuilding programmes. Use this to show that war can destroy economies in the short term but also force long-term restructuring.
· Vietnam War, Asia and Oceania: bombing, chemical warfare, destruction of villages and infrastructure, and post-war isolation damaged Vietnam’s economy. Use this to connect military methods to economic consequences.
· Iran–Iraq War, 1980–1988, Africa and the Middle East: prolonged war damaged oil infrastructure, drained state finances and left both states economically weakened. Use this as an example of a war with high costs but limited territorial gain.
· Nigerian Civil War, 1967–1970, Africa and the Middle East: war disrupted oil production and caused severe economic strain, especially in Biafra. Use this to link economic impact with humanitarian and demographic effects.

Social and demographic impact

· Social impact includes changes to class relations, national identity, education, family life, minority treatment, veterans’ status and civilian experience.
· Demographic impact includes deaths, refugees, famine, migration, displacement, ethnic cleansing, and changes to birth rates or population structure.
· First World War, Europe: mass casualties created a “lost generation”, war widows, disabled veterans and social dislocation. Use this for questions on long-term social consequences of industrialized war.
· Second World War, Europe/Pacific: civilian bombing, genocide, forced labour, occupation and mass displacement made civilians central victims of war. Use this to argue that total war blurred the line between home front and battlefield.
· Spanish Civil War, 1936–1939, Europe: refugees fled Spain, especially after Nationalist advances; post-war repression deepened social division. Use this to show that civil war effects continue after military victory.
· Vietnam War, Asia and Oceania: refugees, veterans, chemical exposure and social trauma affected Vietnam and also influenced US society through protest, distrust of government and veteran reintegration issues. Use this to compare effects on both the war zone and foreign participant.
· Nigerian Civil War, 1967–1970, Africa and the Middle East: famine and civilian suffering in Biafra show how civil war can create demographic catastrophe even when territorial change is reversed.
· Indo-Pakistan War, 1971, Asia and Oceania: mass displacement and violence during the creation of Bangladesh make it useful for essays on demographic change and state formation.

This photograph shows refugees during the evacuation of South Vietnam in April 1975. It supports revision on the demographic and social effects of war, especially displacement after military defeat. Source

Changes in the role and status of women

· The syllabus explicitly names “changes in the role and status of women”, so do not ignore gender when answering effects questions.
· First World War, Europe/Americas: women entered war industries, nursing, transport and public service in greater numbers. Use this to argue that war accelerated social change, although many women were pushed back toward domestic roles after demobilization.
· Second World War, Europe/Americas/Asia: women’s wartime work expanded in factories, agriculture, resistance movements and military support roles. Use this to show that total war increased women’s public roles, but the permanence of change varied by country.
· Spanish Civil War, 1936–1939, Europe: women participated in militias, political organizations and relief work, especially on the Republican side, but Franco’s victory reinforced conservative gender roles. Use this to show that wartime change can be reversed by political outcome.
· Vietnam War, Asia and Oceania: women served as fighters, porters, nurses, labourers and political mobilizers, especially in communist forces. Use this to argue that guerrilla and people’s wars could expand women’s participation in national struggle.
· Chinese Civil War, Asia and Oceania: communist victory promoted official claims of gender reform, including women’s participation in revolutionary society. Use this to link women’s status to ideological outcomes of war.

Compact evidence bank for exam use

· First World War, 1914–1918, cross-regional: use for failed peacemaking, territorial change, economic crisis, mass casualties, and women’s wartime work. Best for essays on extent of change and short-term vs long-term effects.
· Second World War, 1939–1945, cross-regional: use for occupation, territorial restructuring, civilian impact, economic reconstruction, women’s expanded roles, and the shift to a bipolar world order. Best for essays on transformative global effects.
· Spanish Civil War, 1936–1939, Europe: use for authoritarian political outcome, failed reconciliation, refugees, repression, and the reversal of some wartime social change. Best for civil-war comparison.
· Chinese Civil War, 1927–1937 and/or 1946–1949, Asia and Oceania: use for communist victory, regime change, Taiwan/PRC split, and long-term ideological impact. Best for political effects.
· Vietnam War, 1964–1975, Asia and Oceania: use for failed peacemaking, communist victory, economic damage, refugees, and social trauma. Best for foreign involvement and demographic impact.
· Algerian War, 1954–1962, Africa and the Middle East: use for decolonization, Evian Accords, French withdrawal, FLN dominance, and social displacement. Best for linking war to independence and post-colonial politics.
· Nigerian Civil War, 1967–1970, Africa and the Middle East: use for failed secession, Biafra, famine, demographic crisis, and preservation of Nigerian territorial unity. Best for social and demographic effects.
· Indo-Pakistan War, 1971, Asia and Oceania: use for creation of Bangladesh, refugees, state formation, and territorial-political change. Best for direct territorial consequences.

How to compare effects across regions

· Peacemaking comparison: Versailles, 1919 formally ended the First World War but created resentment; Evian Accords, 1962 ended the Algerian War and produced independence, but did not guarantee democratic stability. Judgement: peacemaking may end fighting without resolving political tensions.
· Territorial comparison: First World War redrew borders across Europe; First Gulf War restored Kuwait’s sovereignty and preserved borders. Judgement: effects of war are not always revolutionary; some wars reinforce the existing international order.
· Political comparison: Spanish Civil War produced authoritarian continuity under Franco; Chinese Civil War produced revolutionary communist transformation. Judgement: civil wars often have deeper domestic political effects than interstate wars because they decide who controls the state.
· Demographic comparison: Nigerian Civil War caused famine and internal humanitarian crisis; Vietnam War produced refugees and long-term displacement after the fall of Saigon. Judgement: demographic impact depends on both the conduct of war and the nature of the post-war settlement.
· Women comparison: World Wars expanded women’s labour roles in many states; Spanish Civil War shows that gains could be reversed if the victorious regime promoted conservative gender policies. Judgement: wartime roles do not automatically equal permanent status change.

IB-style argument patterns

· “To what extent did war bring political change?” Argue that effects varied: Chinese Civil War and Spanish Civil War transformed or entrenched regimes, while First Gulf War mainly restored the pre-war territorial order.
· “Evaluate the social and economic effects of two wars.” Pair one total/interstate war with one civil/guerrilla war, for example Second World War and Vietnam War, to compare civilian impact, economic destruction and demographic displacement.
· “Compare and contrast the effects of two wars from different regions.” Use categories: peacemaking, territory, politics, economy, society/demography, women. Do not write two separate mini-essays.
· “Discuss the success of peacemaking after two wars.” Define success as more than ending fighting: consider stability, legitimacy, enforcement, territorial settlement, and long-term tensions.
· Strong judgement phrase: “The most significant effects were not simply the immediate losses of war, but the long-term political settlements and demographic changes that reshaped state power and society.”

Paragraph model for a high-scoring essay

· Point: One major effect of war was long-term political transformation, especially after civil wars.
· Evidence: In the Chinese Civil War, communist victory in 1949 created the People’s Republic of China, while the Guomindang retreated to Taiwan. In the Spanish Civil War, Nationalist victory in 1939 established Franco’s authoritarian regime.
· Analysis: Both wars show that civil wars can decide the ideological direction of the state, but the outcomes differed: China experienced revolutionary communist restructuring, while Spain experienced conservative authoritarian consolidation.
· Judgement: Therefore, the political effects of civil war were often deeper and longer-lasting than territorial effects, because victory determined the nature of government and opposition for decades.

Exam traps or common mistakes

· Writing narrative instead of analysis: do not retell the war; focus on effects after or because of war.
· Ignoring the syllabus categories: include peacemaking, territorial, political, economic, social/demographic, or women’s roles depending on the question wording.
· Using only one region: Paper 2 questions may require two regions, so prepare at least one Europe, one Asia and Oceania, and one Africa and the Middle East example.
· Treating suggested examples as compulsory: IB examples are suggestions only, but your chosen wars must be precise and relevant.
· Confusing causes with effects: nationalism, ideology and economic problems may be causes in one paragraph, but effects paragraphs must show what changed after war.
· Overclaiming women’s emancipation: wartime work did not always produce permanent equality; always judge extent and continuity/change.