World War I causes

Five key causes of World War I

What caused World War I? The ready answer refers to the assassination of Archduke Franz Ferdinand. But there was more to it than that. This article, accompanied by a short explanatory video, outlines how mutual defense alliances, imperialism, militarism, and nationalism also had a heavy hand in the start of what some considered a "preventable war."

How WWI began with the assassination of Archduke Franz Ferdinand

World War I started for several reasons—imperialism, militarism, nationalism, and more—but the catalyst was the assassination of Archduke Franz Ferdinand and his wife Sophie, the Duchess of Hohenberg by the young assassin Gavrilo Princip. Read this article ton see how the assassination sparked the chain reaction that led to the Great War.

Who started WWI?

World War I started with the assassination of the Archduke Franz Ferdinand and his wife Sophie, Duchess of Hohenberg. That's certainly one of the biggest catalysts for the war, but who started it? Ten historians offer their interpretations of which nations bore the brunt of the responsibility. As this article unsurprisingly discovers, it's complicated.

Illustrating the beginning and end of WWI through maps

In August of 1914, Germany invaded an ostensibly neutral Belgium, kick-starting World War I. The war became one of the deadliest conflicts in human history, decimating Europe and reshaping global politics for the next century. It also brought forward sweeping and terrifying new military technologies, a product of the Industrial Revolution. Explore 40 maps explaining the Great War in detail.

Who was impacted by the first world war, and how?

This interactive map from the National Archives in the UK details the global impact of World War I. Countries and territories from Aden to New Zealand were impacted by the Great War, which started in 1914 and lasted until 1918. By selecting various locations on the map, viewers can access articles and evidence on how the war's influence traveled far beyond the front lines.

Was WWI really the first world war?

Was World War I the first true international conflict? This article thoroughly explores the meaning of the term world war. It also suggests a few previous conflicts, some of which involved battles in the Americas as well as Europe, that might have been more accurately described as a "world wars."

An interactive timeline of the major events of World War I

World War I took place between July 28, 1914 and November 11, 1918, but a lot happened within that relatively short time. And even more occurred afterward. The comprehensive timeline shows when major and influential events took place during the conflict, accompanied by articles, videos, and other media in support.

The Concert of Europe's collapse contributed to World War I

The 19th-century great power system gradually unraveled due to rising nationalism, imperial rivalry, and shifting alliances—leading to its collapse in 1914 and the outbreak of the deadliest war the world had yet seen.

Everything you need to know about WWI

Summarizing World War I seems like an impossible task, but this article makes a great effort at providing a easily digested survey of the Great War. Read about WWI from the first shots fired by assassin Gavrilo Princip at the Archduke Franz Ferdinand and his wife Sophie, to the various campaigns waged by the war's participants, to the equipment provided to the various fighting forces.

The treaty that ended the First World War laid the groundwork for the Second.

A visual summary of WWI

This animated video summarizes the "Great War"—World War I—tracing its progression through Europe, detailing the rise of nationalism in the middle of the 19th century until the signing of the peace treaties after 1918. This 18-minute provides a year-to-year accounting of the war with various helpful insights along the way.

The failures of the interwar period made the case for a new international system

After World War I, countries devalued their currencies, raised tariffs to block imports, and seized territory unchecked, with the international community unable to organize effectively to stop them. The result was a global depression and, eventually, another world war.

100 ways the Great War changed the world

What was the point of WWI? What impacts did it have? How has it influenced life today? Click through this Wall Street Journal photo gallery to find out.

Exploring World War I technology on the battlefield

Industrialization brought massive changes to warfare during the Great War. Newly-invented killing machines begat novel defense mechanisms, which, in turn spurred the development of even deadlier technologies. Nearly every aspect of what we would consider modern warfare debuted on World War I battlefields. Starting with soldiers on horseback carrying lances and ending in poison gas, machine guns, and aerial battles, this gallery shows the first tools of modern warfare.

How the Great Depression and end of WWI paved the way for Hitler's rise to power

The end of WWI was triggered by an armistice that blamed the conflict on Germany and required the financially struggling country to pay reparations. This outraged nationalists and ignited conspiracies that Hitler was able to capitalize on, according to this six-minute video. It was during this financial strain that the Great Depression hit.

A global interactive guide to the first world war

Using rarely seen films, new reports of the day, and interactive maps, 10 historians provide a summarized history of the Great War, World War I. During the course of this half hour film, get a variety of insights and perspectives on the so-called "war to end war" and its long-reaching effects.

How the US entered WWI in 1917

Originally taking a position of neutrality during the course of World War I, the United States of America eventually relented. Entering the war in 1917, support for the British and French had risen and Americans were incensed by Germany's overtures to Mexico and U-boat attacks that sank ships and ended American lives. See how and why the US entered WWI in this article.

Explaining the final battle of World War I

The Meuse-Argonne Offensive was the last battle of the First World War. Beginning in September and ending November 11, 1918, the battle was a tumultuous event and the first time the American Army fought on the world's stage. America simultaneously achieved victory and discovered new methods to fight a war. This Apple History podcast provides the details.

Wartime conferences exposed cracks in the US–Soviet alliance

At the Tehran, Yalta and Potsdam Conferences, Allied leaders coordinated WWII strategy—but deep disagreements over postwar Europe foreshadowed the Cold War. The USSR’s push for influence in Eastern Europe clashed with US and British calls for self-determination.

The widespread violence of World War I birthed surrealism

Following World War I, artists used unconventional forms of expression to make sense of the death and destruction they'd witnessed for years. Life as they knew it had ended, and movements like Surrealism, founded by André Breton, rebelled against tradition.

Should the US have entered into World War I?

America entered World War I in 1917, but had remained neutral until that point. President Woodrow Wilson addressed Congress, further underlining the USA's neutrality. Eleven weeks later, he asked for a declaration of war. With attacks by German saboteurs on an American munitions depot, it seemed he had no choice. But did he? This article asks what might have happened if the US stayed out of WWI.

The 1915 sinking of the British RMS Lusitania by the German army precipitated World War I.

How failures at Versailles Conference led to more racial inequality

Suffering a pandemic and the aftermath of a war that killed 50 million, the world in 1920 faced a turning point as it negotiated a new political order. As today, the key issue was racial inequality.

How World War I ended in 2010

Germany made its final reparations-related payment for the Great War on Oct. 3, nearly 92 years after the country’s defeat by the Allies. What took Germany so long to pay for the war?

What happened on WWI's Italian Front?

The battle in the Dolomites, or the White War, might have been the roughest, most arduous, and deadliest conflict during World War I. Italian and Austrian troops fought for control of the Dolomites mountain range over the course of three years, leading to the deaths of 700,000 Italian soldiers and 350,000 Austro-Hungarian troops. A grim account of a dirty little war high in the Dolomites.

Detailing the horrific conditions of life in the trenches

What was it like to live and fight in a trench during World War I? If you were on the German side you might have bunkers, electricity, and other basic comforts. If you were on the British and French side the conditions have been described as muddy and "horrific". Find out how unpleasant trench warfare was and how it affected WWI soldiers.

Japan's imperial expansion in Asia in the 1930s set the stage for war with the US.

,

Why wasn't German emperor Kaiser Wilhelm punished for starting WWI?

The accusations were explosive: a head of state had not only begun an illegal war, but egged his troops on to a series of horrific atrocities that left

Franklin D. Roosevelt's 1941 speech framed World War II as a global fight for universal rights

Eleven months before the attack on Pearl Harbor, President Roosevelt outlined four fundamental freedoms that, in his words, people "everywhere in the world" ought to enjoy—speech, worship, freedom from want, and freedom from fear.

The Great Depression was an international depression felt far beyond the US

Many countries suffered through a depression in the 1930s that the First World War, the US stock market crash, and an economic downturn in Germany turned into an international crisis.

Why were tanks invented?

Tanks first appeared in warfare in World War I. As old methods of conducting battles proved ineffective, the idea of an armored vehicle that could traverse almost any terrain and carry a cannon came to fruition. World War I provided the impetus and finances to develop the modern tank. Learn more in this short but detailed article.

How World War II affects your wallet today

The world's deadliest conflict also impacted social programs extensively, including ways that still affect your money today. World War II is responsible for the practice of employers withholding tax payments and sponsoring health insurance, as well as the norm of providing school lunches for the nation's schoolchildren. Watch this brief video to learn more.

What impact did WWI have on the US civil rights movement?

One of the great hypocrisies in American history involve the expectation of African-Americans to defend liberty in several wars while being deprived of it when they returned home to, as this article puts it "disfranchisement, segregation, debt peonage and racial violence." The writer reflects on World War I and how it affected the fight for civil rights in the USA.

How much did WWII cost?

Though it lasted fewer than four years, World War II was the most expensive war in United States history, according to this infographic. Read through it to see how much WWII cost and learn about the consequences of financing such an expensive conflict.

Timeline: the Middle East conflict

During the First World War, Western and Arab powers negotiated the future political status of Arab lands. Since WWI, a complex history of political, economic, and social events have fueled tension and violence between Israel and Palestine. This timeline, compiled by Al Jazeera, highlights important global events defining conflict in the Middle East from 1915 to 2007.

The 20th-century rise of fascism affected the World Cup

Spain, in the midst of a civil war, did not participate, and Japan, after invading China, pulled out of the competition. An additional six Central and North American teams scratched by the time that year's World Cup began.

Why did the Ottoman Empire violently target Armenians during WWI?

In anticipation of threatened Allied landings at the strategically important Gallipoli peninsula, Ottoman authorities arrested 240 Armenian leaders in Constantinople on April 24, 1915, and deported them east. This roundup is commemorated today by Armenians as the beginning of the genocide, according to this article.

The “Phoney War” was an eight‑month build-up to war

From September 1939 to May 1940, following their war declaration on Germany, Britain and France entered a phase of military inaction—even as civil defence measures, naval blockades, and rationing intensified at home. Skirmishes were limited, but the decisive fighting didn't begin until Germany invaded Norway and France in April–May 1940, abruptly ending the uneasy stalemate.

The US and allies invaded Iraq based on flawed intelligence about potential weapons of mass destruction.

The Cold War (1947-1991) prompted the birth of NATO and the Soviet Warsaw Pact

The geopolitical rivalry between the United States and Soviet Union was considered “cold" because the two countries never directly engaged in military combat during the time period. This page from the Kennedy Presidential Library outlines the causes and major events of the early Cold War.

World War I brought attention to US reliance on mineral imports

Domestic stockpiles were inadequate for the extended trade disruptions caused by the four-year war. In response, the US Geological Survey increased its geological mapping to help search for important metals alongside new oil fields for fuel.

The Russian Revolution toppled the tsar and brought the Bolsheviks to power

In 1917, mass unrest, war exhaustion, and economic collapse overthrew the Romanov monarchy, enabling the Bolsheviks to seize control. The revolution dismantled imperial Russia and set the foundation for the creation of the Soviet Union.

Germany’s invasion of Poland in 1939 launched World War II

On September 1, 1939, Nazi Germany launched a surprise invasion of Poland using blitzkrieg—coordinated air bombardments and armored assaults—to overwhelm Polish defenses within weeks. This lightning-strike strategy shocked the world and signaled both the start of World War II and a revolutionary shift in modern military tactics.

World War II helped convince food companies to produce more processed foods

Processed foods had existed since the 19th century, but they began infiltrating the mainstream during World War II, with foods designed to last on the battlefield for days. After the war, food companies saw great potential in the relatively cheap foods aimed at busy households. (Some readers may experience a paywall.)

The Russia-Ukraine war greatly affected the global food supply

Russia's invasion devastated Ukraine's agricultural sector, destroying farms, ports, and grain infrastructure and causing over $40B in losses. Disrupted exports fueled global food insecurity, while Moscow leveraged its grain exports to expand influence across the Global South.

The final war between the Persian and Byzantine empires

The Arab conquests of the seventh century, which swept over Egypt, Syria, and Mesopotamia, were made possible by a catastrophic generation-long war between the Byzantine and Persian Empires. That war, in turn, was the last act in a struggle that had gone on for centuries, and shaped the whole subsequent history of the Middle East.

The world rapidly decolonized after World War II, with roughly a hundred new countries emerging between 1945 and 1989.

Decolonization isn't complete, as nearly 2 million people were living in UN-designated non-self-governing territories as of 2023.

In 1914, the Financial Times asked readers to redraw Europe for cash prizes

Two months in World War I, the newspaper invited readers to sketch postwar borders and submit peace terms for cash prizes. The contest captured public attempts to predict a new world order and foreshadowed modern crowdsourced forecasting. It's a wild look at how uncertain Europe's future was at the time.

Hitler's 1941 invasion of the USSR doomed Nazi Germany

Hitler unleashed Operation Barbarossa on June 22, 1941, underestimating Soviet resilience, Russian winter, and logistics. His overconfidence—rooted in early victories like France—turned this campaign into a strategic catastrophe, shifting the war’s momentum irreversibly—often cited as his greatest blunder.

The US launched the Global War on Terror after 9/11

In the wake of 9/11, the US declared a Global War on Terror—initiating military operations in Afghanistan and Iraq, expanding surveillance, and forming international coalitions to combat terrorism and disrupt extremist networks worldwide.