Unit 7: Global Conflict

Shifting Global Power and the Roots of Conflict (c. 1900–1914)

By 1900, much of the world had been colonized by European powers (or shaped by earlier European colonization), and global trade and imperial networks tightly connected regions to one another. That meant instability in Europe could ripple outward quickly. Industrialization, imperial competition, and expanding global markets created prosperity for some, but they also raised the stakes: when economies, empires, and militaries become interdependent, a crisis in one place can spread rapidly.

Industrialization, empire, and competition

A useful way to understand early-1900s tensions is to picture an increasingly crowded marketplace. Industrialized states needed raw materials, markets, and strategic ports to protect trade routes, and empires provided all three. As newer industrial powers sought colonies comparable to older empires, rivalry intensified.

Industrialization also reshaped military power. Mechanized production let states build larger armies, bigger navies, and vast stockpiles of weapons. Leaders sometimes convinced themselves that a quick, decisive war would be possible, but industrial warfare often produced stalemate and massive casualties instead.

Concrete examples of competitive pressures include Britain–Germany naval rivalry (shipbuilding as a symbol of national power) and continuing imperial competition across Africa and Asia even after the “scramble” slowed.

Nationalism: unity and danger

Nationalism is the belief that a people with shared identity (language, culture, history) should have political self-rule and that loyalty to the nation should come first. In the 1800s, nationalism helped unify Germany and Italy; by the early 1900s it also destabilized multiethnic empires.

The Ottoman Empire, for example, was widely seen as weakening as it lost territory over time (including earlier losses connected to Greek independence and growing Slavic national movements in the Balkans). Austria-Hungary also contained many ethnic groups with competing nationalist goals. Nationalism was not just an “idea”: it appeared in political organizations, newspapers, student movements, and sometimes armed groups.

A key point for AP World is to avoid assuming nationalism always pushes toward democracy. It can support self-determination, but it can also fuel militarism, ethnic exclusion, and claims of superiority.

Militarism and alliance systems

Militarism is the belief that military strength is essential to national success and that military solutions are acceptable tools of policy. In early-1900s Europe, detailed war planning and rigid mobilization timetables reduced diplomatic flexibility.

Alliances were meant to deter enemies, but they also made escalation more likely by turning regional crises into wider wars. By the early 1900s, major alignment patterns included:

• Triple Alliance (1880s): Germany, Austria-Hungary, Italy (in part to protect against France)
• France–Russia alliance: aimed at keeping Germany in check
• Triple Entente: Britain, France, Russia (Japan later joined the Entente/Allied side during WWI)

The AP priority is less about memorizing every treaty and more about explaining the mechanism: alliance expectations and mobilization plans made it harder to contain crises.

Why conflict became “global”

Conflict became global because empires made it global. When European powers fought, they drew in colonies and dominions through colonial troops, imperial resources, and worldwide strategic interests. Naval warfare also disrupted global shipping lanes and trade routes.

Exam Focus

• Typical question patterns
  • Explain how industrialization and imperialism increased tensions among states before WWI.
  • Compare how nationalism affected stability in multiethnic empires (Ottoman vs. Austria-Hungary).
  • Analyze how alliance systems transformed a regional crisis into global conflict.
• Common mistakes
  • Treating “alliances caused WWI” as a complete explanation—alliances spread war, but underlying rivalries and militarism mattered.
  • Ignoring empire: WWI is often taught as “European,” but AP expects you to connect it to colonial troops, resources, and global theaters.

Causes of World War I (1914)

World War I is best understood as an escalation problem. European leaders expected crises; what they failed to manage was controlling escalation once a major shock occurred. The assassination at Sarajevo mattered, but it acted like a spark in a room filled with fuel.

Long-term causes: pressures that built over decades

Historians often group long-term causes into M.A.I.N. (militarism, alliances, imperialism, nationalism). Instead of treating this as a checklist, focus on how the factors interacted:

1. Imperial rivalry created distrust and repeated diplomatic clashes.
2. Nationalism intensified interstate rivalries and threatened multiethnic empires.
3. Militarism expanded armies/navies and encouraged rigid war planning.
4. Alliance commitments reduced flexibility once crises began.

The immediate trigger: Sarajevo and the July Crisis

Bosnia and Herzegovina had come under Austro-Hungarian control through late-1800s diplomacy (including arrangements associated with the Berlin Conference of 1878). In June 1914, Archduke Franz Ferdinand of Austria-Hungary visited Bosnia and was assassinated in Sarajevo by Gavrilo Princip, a Bosnian Serb nationalist connected to broader Serbian nationalist aims.

Austria-Hungary treated Serbia as a threat to imperial stability and issued a harsh ultimatum. Escalation followed quickly:

• Austria-Hungary moved against Serbia.
• Russia mobilized to support Serbia.
• Germany backed Austria-Hungary and viewed Russian mobilization as a major threat.
• France supported Russia.
• Britain entered after German actions violated Belgian neutrality and threatened the balance of power.

German war planning included the Schlieffen Plan, which involved attacking France by moving through neutral Belgium—a key step in widening the war.

A common misconception is that “everyone wanted war.” Some leaders did; others hoped to avoid it. But once mobilization began, leaders feared slowing down would be strategically fatal.

Who fought: alliances and global participation

During the war, the Central Powers centered on Germany, Austria-Hungary, and the Ottoman Empire (with other states joining later). The opposing side is often described as the Allies/Entente powers, and participation expanded over time.

WWI also drew in an unusually large number of states; classroom summaries often note that over 40 countries became involved, in part because colonial connections and imperial obligations pulled territories and troops into the conflict.

The United States enters the war

The United States had a longstanding tendency toward isolationism (neutrality and a focus on internal affairs rather than European alliances). It entered the war on the Allied side in 1917 after multiple pressures, including Germany’s submarine warfare affecting shipping, the sinking of the Lusitania in 1915 (with over 100 American passengers), and the Zimmermann Telegram (1917), in which German diplomacy encouraged Mexico to join Germany and suggested Mexico could regain territory lost to the United States.

Global dimensions from the start

Even early in the war, fighting and consequences were not limited to Europe:

• Fighting occurred in parts of Africa as empires attacked each other’s colonies.
• The Ottoman Empire joined, expanding conflict into the Middle East.
• Naval warfare and disrupted trade affected economies worldwide.

Exam Focus

• Typical question patterns
  • Provide two long-term causes of WWI and explain how they contributed to outbreak.
  • Explain how the assassination in Sarajevo triggered alliance obligations.
  • Analyze WWI as a consequence of imperialism and nationalism.
• Common mistakes
  • Writing only the assassination as the cause; AP readers look for long-term causes and escalation logic.
  • Describing alliances without explaining the chain reaction (who supported whom and why it mattered).

How World War I Was Fought: Total War, Technology, and Empires (1914–1918)

World War I demonstrated what happens when industrial capacity, mass conscription, and modern weaponry collide with rigid military planning. The result was often stalemate, enormous casualties, and societies reorganized around war.

Trench warfare and the problem of stalemate

On the Western Front, armies dug into trenches because defensive firepower was overwhelming. The recurring pattern was grim: artillery barrages, infantry attacks across “no man’s land,” devastating defensive fire, and minimal territorial change. The key concept is the mismatch between offensive strategy and defensive technology.

New technologies and changing warfare

WWI featured major developments and widespread use of:

• Machine guns and rapid-fire artillery
• Poison gas
• Tanks (early models were unreliable but signaled mechanized warfare)
• Aircraft (reconnaissance evolving into combat roles)
• Submarines (especially German U-boats targeting shipping)

On AP-style questions, listing technologies is less effective than explaining what they changed: tactics, casualty rates, stalemate dynamics, and pressure on civilian economies.

Total war: what it means and why it matters

Total war describes the mobilization of an entire society for victory, shrinking the line between front line and home front. Governments expanded state power through rationing, propaganda, and censorship; civilian labor and industry were redirected toward war production; and civilians faced shortages and growing danger.

Examples include governments directing industrial output toward weapons, rationing food and fuel, propaganda campaigns to maintain morale, and recruiting women into wartime industries.

Colonial troops and imperial resources

European empires drew heavily on colonies for manpower and materials. Soldiers from places such as India and North Africa fought in multiple theaters, while colonies supplied food, minerals, and cash crops. This deepened colonial sacrifice and disruption and encouraged many colonial subjects to expect reforms or autonomy afterward—setting up later tensions and independence movements.

The United States and the shifting balance

U.S. entry in 1917 mattered less as a single “cause” and more as a shift in resources and morale. American involvement increased Allied access to supplies, financing, and fresh troops, shaping the war’s later balance.

The Russian Revolution and the Eastern Front

WWI intensified Russia’s internal crises: shortages, military losses, and loss of confidence in the monarchy. Background factors also included earlier shocks such as Russia’s loss in the Russo-Japanese War (1904–1905) over Manchuria-related influence and the 1905 unrest marked by “Blood Sunday,” when troops fired on peaceful protestors.

In 1917, Czar Nicholas II was forced to resign. Alexander Kerensky led a provisional government, but it struggled, including because it conflicted with local councils known as soviets (representing workers, peasants, and soldiers). The Bolsheviks, led by Vladimir Lenin, gained support with Lenin’s April Theses, which demanded peace, land for peasants, and power to the soviets. Within months, the Bolsheviks seized power, and the state that emerged would soon be known as the Soviet Union.

Russia’s exit from WWI was formalized in the Treaty of Brest-Litovsk (1918), an armistice/peace with Germany that ceded parts of western Russia. Civil conflict followed as counterrevolutionary movements challenged Bolshevik rule; the Bolsheviks created the Red Army under Leon Trotsky to defeat these forces. The revolutionary outcome also introduced a powerful new ideological model (communism) and left the Soviet state deeply distrusted by many Western neighbors.

Wartime violence in the Ottoman Empire and the rise of Turkish nationalism

During the war, Ottoman leaders framed Armenians as an internal threat and carried out mass killing and deportations widely recognized by historians as genocide. The war years also accelerated a shift toward Turkish nationalism. In the postwar struggle, Mustafa Kemal (Atatürk) led successful resistance (including against invading Greek forces), overthrew the Ottoman political order, and became the first president of modern Turkey.

Human cost

The war’s casualties were staggering. Some commonly cited figures include roughly 8.5 million soldiers killed, and figures for civilian deaths vary widely by methodology; some classroom summaries cite around 20 million civilian deaths. What matters historically is the broader point: industrial war and total war pressures produced death and suffering on a scale that shocked contemporaries.

Exam Focus

• Typical question patterns
  • Explain how total war affected civilian populations and state power.
  • Analyze how new military technologies changed warfare in WWI.
  • Explain how empires used colonies in fighting WWI and how that affected colonial societies.
• Common mistakes
  • Treating “new technology” as automatically decisive; in WWI, technology often increased stalemate and casualties rather than producing quick victory.
  • Forgetting the global perspective: colonies, dominions, and non-European theaters are frequently expected evidence.

Ending World War I and Reshaping the World Order (1918–1920s)

Wars end twice: first on the battlefield, then at the negotiating table. How WWI ended helped create resentment, economic strain, and border disputes that destabilized the interwar world.

Armistice and political collapse

By 1918, exhaustion, shortages, and military setbacks undermined the Central Powers. Fighting ended with an armistice in November 1918, but the armistice itself did not resolve the war’s deeper tensions.

The Treaty of Versailles and the “peace problem”

The Treaty of Versailles (1919) officially ended WWI and imposed major terms on Germany, including territorial losses, military limits, war guilt, and reparations. The AP-level takeaway is why the treaty became controversial: many Germans viewed it as humiliating, and it failed to create a stable balance. The resulting poverty, resentment, and political instability contributed to later extremist politics, including Hitler’s rise.

A related tension was the departure from U.S. President Woodrow Wilson’s Fourteen Points, which emphasized a more workable peace and future stability. Britain and France pushed harsher punishments on Germany, reflecting their own security fears and domestic political pressures.

Redrawing borders and the self-determination dilemma

Borders changed dramatically, and applying national self-determination proved difficult in mixed-population regions. One example of postwar state reconfiguration was the breakup of Austria-Hungary, with successor states including Czechoslovakia. These changes often created new minorities, new grievances, and new border disputes.

Mandates and the Middle East

Former Ottoman territories were placed under European mandates, presented as temporary stewardship but often experienced locally as a continuation of imperialism. This continuity of imperial control helped fuel anti-imperial resentment.

The League of Nations and collective security

The League of Nations aimed to prevent future wars through diplomacy and collective security. Wilson promoted its formation as a council of nations to preserve peace and advance humanitarian goals, but it was not widely accepted or consistently supported (including the United States’ refusal to join).

The League struggled because enforcement required major powers to agree on consequences and accept costs, something many were unwilling to do—especially during economic crisis.

Exam Focus

• Typical question patterns
  • Explain how the Treaty of Versailles contributed to interwar instability.
  • Analyze the challenges of applying self-determination after WWI.
  • Explain how mandates reflected continuity of imperialism.
• Common mistakes
  • Assuming new borders matched ethnic realities; many did not, which is the point.
  • Treating the League’s failure as purely “it was weak” without explaining why enforcement failed.

Interwar Upheaval: Depression, Ideological Conflict, and the Rise of Authoritarian States (1920s–1930s)

The interwar period is best understood as a time when unresolved problems intensified. Economic crisis and social fear made radical solutions attractive, and many governments expanded their control over economies and societies.

The Great Depression as a global turning point

The Great Depression began with the 1929 stock market crash and spread globally through interdependence. War debts and reparations left parts of Europe financially entangled with U.S. lending; when credit contracted and trade collapsed, the crisis became international. Export-dependent regions were hit hard as demand for raw materials fell. Unemployment soared; some summaries note that the United States and Germany were among the hardest hit, with unemployment reaching roughly one-third of the workforce in some periods.

The Unit 7 significance is that economic collapse weakened faith in liberal democracy and market capitalism and made authoritarian promises of order and national revival more appealing.

Competing economic and political responses

AP World often asks you to compare how different systems responded.

Liberal reform in capitalist democracies

Some states increased government intervention while maintaining democratic institutions. In the United States, the New Deal expanded government involvement in relief and regulation. The key trend is increased state management of economic life without fully abandoning democratic structures.

Communism in the Soviet Union: NEP to Stalinism

After the revolution, Lenin introduced the New Economic Policy (NEP) in the 1920s, allowing farmers to sell portions of their grain for profit. After Lenin’s death, Joseph Stalin discarded the NEP and pursued Five-Year Plans emphasizing rapid, state-directed industrialization and collectivization (bringing agriculture under state control).

Mechanism-wise, this meant production targets set from the top down, prioritizing heavy industry, and reorganizing rural life to fit state goals. Stalin’s modernization relied heavily on coercion and terror, including secret police, show/bogus trials, imprisonment, and assassinations—an increasingly totalitarian approach.

Fascism and militarized economies

Fascism is an ultranationalist, authoritarian ideology that emphasizes unity under a strong leader and subordination of the individual to the state, often through violence against perceived enemies. Fascists sought a unified society (somewhat like communists in rhetoric of unity) but generally did not eliminate private property or erase class distinctions; instead, they subordinated economic and social life to national goals.

Fascist states typically pursued militarization, aggressive nationalism and expansion, propaganda, and political repression. AP answers are stronger when fascism is defined specifically (ultranationalism, mass mobilization, repression, often racial/ethnic hierarchy), not simply as “a dictatorship.”

Fascism in Italy

Italy became the first fascist state under Benito Mussolini, who founded a fascist movement in 1919. Paramilitary squads known as the Blackshirts attacked socialist and communist organizations and helped Mussolini gain support among factory owners and landowners. The Italian king appointed Mussolini prime minister, and Mussolini faced little effective opposition as he consolidated power and took control of Parliament in 1922.

The rise of Hitler in Germany

After WWI, the German emperor abdicated and Germany became a conservative democratic republic known as the Weimar Republic, with an elected legislature called the Reichstag. Economic crisis and political instability undermined confidence in the Weimar system, and the National Socialist Party (Nazis) rose in the 1920s and early 1930s.

Adolf Hitler promoted extreme nationalism and racist ideology, including belief in an Aryan “superior race.” By 1932, the Nazis were the dominant party, and in 1933 Hitler became chancellor and rapidly dismantled democratic constraints; his regime is known as the Third Reich.

Japan and militarism

Japan industrialized rapidly and pursued imperial ambitions. Japan’s global standing increased in the early 1900s, including through a diplomatic relationship/alliance with Britain (first formalized in 1902 and renewed later, contributing to Japan’s international status). After WWI, Japan’s economy thrived for a time, but the Great Depression strengthened militarist arguments that expansion was necessary for security and resources.

Japan invaded Manchuria in 1931 and established Manchukuo, withdrew from the League of Nations, and later signed the Anti-Comintern Pact with Germany (positioning itself against communism). In 1937, Japan expanded war against China—conflict that would merge into WWII.

Social tensions, propaganda, and scapegoating

Interwar instability often produced scapegoating of minorities and political opponents. Propaganda portrayed internal “enemies” as responsible for national decline, increasing repression and normalizing violence. These patterns helped enable later mass atrocities by combining dehumanizing ideology with strong state power.

Exam Focus

• Typical question patterns
  • Compare responses to the Great Depression in different states (liberal reform vs. communism vs. fascism).
  • Explain how economic crisis contributed to the rise of authoritarian regimes.
  • Analyze how Japan’s expansion was connected to resource needs and militarism.
• Common mistakes
  • Treating the Great Depression as only a U.S. event; you must explain its global effects.
  • Defining fascism too broadly; be specific about ultranationalism, mass mobilization, and repression.

Causes of World War II: Expansion, Appeasement, and the Failure of Collective Security (1931–1939)

World War II emerged through expansionist moves that tested the international system and revealed that enforcement mechanisms were weak. Aggression became more likely when aggressors concluded they would not face decisive consequences.

Expansionism as a strategy

Expansionism is a policy of extending a nation’s territory or influence through conquest, colonization, or intimidation, often justified with nationalist claims about resources, security, ethnic kin, or “living space.” Key examples include:

• Japan’s seizure of Manchuria (1931)
• Italy’s invasion of Ethiopia (1935)
• Germany’s systematic violation of the Versailles settlement through rearmament and expansion

In Europe, Hitler’s expansion escalated step-by-step: remilitarizing the Rhineland, building ties with militarist Japan, annexing Austria, and gaining the Sudetenland at the Munich Conference (1938) (with Hitler, Mussolini, and British Prime Minister Neville Chamberlain) as part of an attempted settlement.

The League of Nations and collective security breakdown

The League struggled to stop aggressors because collective security requires major powers to agree on action and accept costs. During the Depression and amid domestic political constraints, many governments hesitated. When enforcement fails, aggressors learn that risks are low, while potential victims lose confidence and may rearm.

Appeasement: why it happened and why it failed

Appeasement is the policy of making concessions to an aggressive power to avoid war. It was shaped by WWI trauma, belief that some Versailles grievances were legitimate, fear of communism, and limited immediate military readiness. Appeasement failed when concessions signaled that aggression would be rewarded.

Germany’s continued actions showed this clearly: after Munich, Hitler invaded the rest of Czechoslovakia in 1939. Italy also pursued aggression, including the invasion of Albania in 1939.

The Spanish Civil War and authoritarian consolidation

Spain’s turmoil after the fall of the monarchy led to civil war. Nationalist forces under General Francisco Franco received support from Germany and Italy. Franco established a dictatorship in Spain in 1939, illustrating how ideological conflict and foreign intervention destabilized Europe on the eve of WWII.

Immediate outbreak in Europe: invasion of Poland

Germany signed the Nazi–Soviet Pact, agreeing (among other terms) to non-aggression and to divide spheres of influence in Eastern Europe. Germany then invaded Poland in 1939; Britain and France declared war, marking the start of WWII in Europe.

War in Asia before 1939

In Asia, large-scale conflict began earlier, especially with Japan’s 1937 war in China. AP World emphasizes that WWII was global partly because major fighting in Asia preceded 1939 and then merged into a broader world conflict.

Exam Focus

• Typical question patterns
  • Explain how expansionist policies in the 1930s contributed to the outbreak of WWII.
  • Analyze the failure of collective security and the League of Nations.
  • Evaluate appeasement: why it seemed attractive and why it backfired.
• Common mistakes
  • Writing appeasement as a moral judgment only; you need cause-and-effect reasoning.
  • Treating WWII as starting only in 1939 without recognizing earlier Asian conflict.

Conduct of World War II: Total War at a New Scale (1939–1945)

World War II intensified patterns seen in WWI—total war, expanded state power, and civilian suffering—but on a far greater scale. Combat, occupation, and genocide produced catastrophic civilian death, and the war ended with the use of nuclear weapons.

Rapid offensives and a multi-front war

In Europe, Germany’s early strategy relied on fast, coordinated assaults using infantry, armor, and air power—often described as blitzkrieg. By early 1940 Germany had conquered or controlled Poland (with the eastern portion under Soviet occupation per the Nazi–Soviet Pact), as well as Holland, Belgium, and France.

Britain, led by Prime Minister Winston Churchill, refused to surrender even under heavy air attacks during the Battle of Britain. Over time, the war widened into multiple fronts: Western Europe and the Atlantic, the Eastern Front, North Africa and the Mediterranean, and the Pacific and East/Southeast Asia.

Germany expanded the conflict further in 1941, including campaigns in Greece and the invasion of the Soviet Union, making the Eastern Front extraordinarily destructive and occupation policies especially brutal.

The home front: economies reorganized for war

WWII required enormous production of weapons, vehicles, aircraft, and supplies. States expanded control over labor, industry, and information using planning boards, rationing and recycling campaigns, and propaganda. Women’s roles in the workforce expanded dramatically in many industrial economies due to labor shortages.

When writing about total war, emphasize the mechanism: governments needed resources, so they increased control; increased control reshaped daily life; daily life became part of the war effort.

Civilians as targets

Civilian suffering increased dramatically due to strategic bombing, sieges and starvation policies, occupation regimes using forced labor and collective punishment, and mass atrocities.

A common mistake is to claim civilians were targeted “for the first time” in WWII. Civilians suffered in earlier conflicts too (including WWI). The difference in WWII was the scale, intensity, and the systematic nature of certain policies.

Resistance, collaboration, and the complexity of occupation

Occupied societies responded in multiple ways. Resistance ranged from armed struggle and sabotage to intelligence networks and underground publishing. Collaboration could stem from ideology, survival, or perceived advantage. Showing this range can add complexity to AP writing by avoiding oversimplified narratives.

The Pacific War and U.S. entry

The United States initially sought to avoid direct involvement, but tensions escalated as Japan expanded across Asia. The U.S. responded to Japanese aggression with measures including freezing Japanese assets, and Japan deepened its alliances through agreements such as the Tripartite Pact with Rome and Berlin.

In 1941 Japan attacked Pearl Harbor in Hawaii, bringing the United States fully into the war. The U.S. accelerated the Manhattan Project, the program to develop the atomic bomb.

Turning points and war’s end

You are not required to memorize every battle, but you should understand that the war’s momentum shifted as the Allies mobilized greater industrial and human resources and as Axis powers overextended.

Key endgame milestones often highlighted in surveys include: Allied advances in Italy (with the U.S. and Britain gaining control in 1943), the 1944 Allied landing in France (D-Day) by U.S., British, and Canadian forces, and the 1945 collapse of Nazi Germany as Allied forces closed in; Hitler committed suicide as defeat became inevitable.

The war ended in Europe in 1945 with Germany’s defeat. In the Pacific, the United States dropped atomic bombs on Hiroshima and Nagasaki in 1945, and Japan surrendered soon after. Historically significant context includes the unprecedented destructive capability of nuclear weapons, the cumulative impact of conventional bombing, and the Soviet Union’s entry into the war against Japan.

Exam Focus

• Typical question patterns
  • Explain how WWII expanded the concept of total war compared to WWI.
  • Analyze how mobilization on the home front contributed to Allied victory.
  • Explain ways civilians experienced WWII (bombing, occupation, forced labor, rationing).
• Common mistakes
  • Giving only battlefield narration; AP responses score higher when they link warfare to state power, economies, and civilians.
  • Treating atomic bombs as the single-cause explanation for Japan’s surrender without acknowledging broader wartime context.

Mass Atrocities, Genocide, and the Human Consequences of Global Conflict

Unit 7 requires confronting a difficult theme: industrialized war and authoritarian ideology made mass killing more systematic and, in some cases, explicitly genocidal. Strong historical explanation focuses on causes and mechanisms rather than vague moralizing.

What counts as genocide and mass atrocity?

Genocide is the deliberate attempt to destroy, in whole or in part, a national, ethnic, racial, or religious group. Not all mass death is genocide; civilians can die in large numbers through bombing, starvation, disease, and displacement without an explicit intent to eliminate a group.

A mass atrocity is broader and can include genocide, ethnic cleansing, mass executions, or systematic terror. Being precise matters on AP questions because these terms imply different intent and mechanisms.

The Armenian Genocide (WWI era)

During WWI, the Ottoman Empire carried out mass killing and deportation of Armenians—widely recognized by historians as genocide. Wartime conditions mattered because leaders framed Armenians as an internal threat during a desperate imperial struggle, showing how fear, nationalism, and state power can enable extreme violence.

The Holocaust

The Holocaust was Nazi Germany’s systematic, state-driven genocide of six million Jews, alongside the persecution and murder of other targeted groups (including Roma, disabled people, Slavs in certain contexts, political opponents, and others targeted by Nazi ideology). It involved ideology and dehumanization, bureaucracy and state capacity (registration, transport, confinement), wartime radicalization, and an infrastructure of killing (ghettos, mass shootings, deportations, extermination camps).

A common misconception is that genocide is “spontaneous chaos.” The Holocaust demonstrates how genocide can be planned, bureaucratic, and industrial in method.

Atrocities in Asia and the Pacific

Japanese imperial expansion included severe atrocities in occupied regions. A widely cited example is the Nanjing Massacre (1937) during Japan’s war in China. Strong explanations connect violence to militarized imperial ideology, dehumanization of occupied peoples, and occupation policies aimed at extracting resources and suppressing resistance.

Displacement, refugees, and long-term trauma

Global conflict produced massive displacement as people fled front lines, occupation regimes, famine, and persecution. Refugee crises reshaped demographics and politics and could intensify nationalist tensions when displaced groups were treated as outsiders or threats. On AP prompts about war’s effects, this civilian dimension is essential evidence.

Exam Focus

• Typical question patterns
  • Explain causes and mechanisms of genocide in the context of global conflict (ideology, state power, war).
  • Compare mass atrocities in different regions (Europe vs. Asia) with attention to both similarities and differences.
  • Analyze how total war contributed to civilian suffering and displacement.
• Common mistakes
  • Using “genocide” to describe all civilian deaths; be clear about intent and targeting.
  • Writing atrocities as isolated events rather than outcomes of ideology + state capacity + wartime conditions.

Consequences of World War II and the Postwar Order (1945 and after)

WWII reshaped global power, accelerated decolonization pressures, and produced new institutions designed to prevent another catastrophic war.

New superpowers, demilitarization, and rebuilding

After the war, the United States and the Soviet Union emerged as dominant superpowers, while Germany and Japan were forced to demilitarize. Europe’s physical and economic devastation prompted major reconstruction efforts. The United States launched the Marshall Plan to rebuild European economies; it was accepted primarily by Western European nations and helped them recover in less than a decade.

Decline of colonialism

The war inspired many colonized peoples to challenge imperial rule. Colonial soldiers’ participation, wartime hardship, and the contradiction between fighting for “freedom” abroad while lacking it at home strengthened anti-colonial movements, contributing to the broader decline of colonial empires.

Big changes for women

Women took on expanded workforce roles while men fought, especially in industrial economies. After the war, many women continued working, contributing to longer-term social and economic change.

Creation of international organizations and a managed global economy

In 1945 the United Nations was established to prevent another great war by mediating and intervening in international disputes. In response to the Holocaust and wartime atrocities, the UN issued the Universal Declaration of Human Rights.

Other institutions formed to manage the postwar global economy included the World Bank, the International Monetary Fund (IMF), and the General Agreement on Trade and Tariffs (GATT).

The Cold War

Tensions between the United States and the Soviet Union hardened into the Cold War, as each sought to prevent the other from expanding its influence. Containment strategies and geopolitical rivalry shaped global politics for roughly the next 50 years.

Exam Focus

• Typical question patterns
  • Explain how WWII shifted global power and contributed to U.S.–Soviet rivalry.
  • Analyze how WWII accelerated decolonization movements.
  • Explain why new international institutions (UN, IMF, World Bank, GATT) formed after WWII.
• Common mistakes
  • Treating postwar rebuilding as automatic; link recovery to policies like the Marshall Plan and to Cold War divisions.
  • Discussing decolonization without connecting it to wartime participation, economic disruption, and changing legitimacy of empires.

Making Unit 7 Arguments: Causation, Comparison, and Continuity/Change (How to Write About Global Conflict)

Unit 7 is heavy on facts, but AP World History rewards historical reasoning: explaining causation, making comparisons, and tracking continuity and change over time.

Causation: building multi-causal explanations

Strong causation writing does three things: names multiple causes, shows relationships among causes, and explains a mechanism (how a cause produces an effect). For example, a connected causation chain for WWII can link Versailles resentment, Depression-era desperation, fascist propaganda, weak collective security and appeasement, and escalating expansionism.

Comparison: WWI vs. WWII (what to compare and how)

Effective comparisons show similarities and differences using consistent categories:

• Causes: alliance escalation and imperial rivalry (WWI) vs. expansionist regimes and failure of collective security (WWII), with overlap in nationalism and militarism
• Conduct: trench stalemate and early mechanization (WWI) vs. faster early offensives, broader civilian targeting, and genocide (WWII)
• Home front: both total war, with WWII generally involving even greater mobilization and more systematic targeting of civilians
• Outcomes: both reshaped borders and global power; WWII more directly set up postwar institutions and ideological bipolarity (bridge to Unit 8)

Avoid writing that “WWII was worse” without explaining why (technology, strategic bombing, genocide policy, broader theaters, etc.).

Continuity and change: what changed from 1900 to 1945?

Strong continuity/change arguments often emphasize:

• Continuity: imperial ambitions persisted even as empires weakened; racism and dehumanization shaped policy; states expanded control over societies in wartime.
• Change: warfare became more mechanized and destructive; civilian targeting increased; international institutions emerged (League of Nations, later the UN) with varying effectiveness.

Anchor these claims in concrete developments like industrial capacity, propaganda techniques, state bureaucracy, and new weapons.

“Show it in action”: mini writing models

These models demonstrate the level of specificity and linkage AP expects.

Example thesis (LEQ-style) about causes of WWII

World War II broke out largely because economic crisis and unresolved post–World War I grievances strengthened authoritarian and ultranationalist movements, while the failure of collective security and the use of appeasement allowed expansionist states to pursue conquest with limited consequences.

Example paragraph move (evidence + reasoning)

The Great Depression undermined confidence in liberal democratic governments because mass unemployment and collapsing trade made parliamentary politics appear ineffective. In Germany, this economic desperation helped extremist parties gain support by promising rapid recovery and national revival, which in turn made aggressive expansion more politically feasible.

Exam Focus

• Typical question patterns
  • Causation prompts about WWI/WWII outbreak and escalation.
  • Comparison prompts (WWI vs WWII; fascism vs communism; responses to Depression).
  • Continuity/change prompts about warfare, state power, and imperialism across 1900–1945.
• Common mistakes
  • Dropping facts without explaining significance (what the fact did).
  • Writing single-cause arguments (“Versailles caused WWII”) instead of layered causation.
  • Confusing categories: mixing up economic causes with ideological ones without showing how they connect.