What were the causes of the First World War?

Statue of WWI soldier with a horse
Source: https://pixabay.com/photos/soldier-horse-helmet-rider-man-1850365/

The First World War was the first conflict that occurred on an industrial scale, involving many countries from all around the world. However, the reason why the war originally began is incredibly complex.


To try and explain the causes of the war, historians have tried to simplify it down to four main causes. They create the acronym: MAIN. 

  • Militarism
  • Alliances
  • Imperialism
  • Nationalism

This simplified acronym is a useful way to remember the four MAIN causes of the war. However, we will explain each of these concepts out of order below.


One of the most commonly discussed causes of WWI was the system of alliances that existed by 1914, the year the war started.


An 'alliance' is an agreement made between two countries, where each side promises to help the other if required.


Most of the time, this involves military or financial assistance. When an alliance is created, the countries involved are known as 'allies'.

By the dawn of the First World War, most European countries had entered into one or more alliances with other countries.


What made this an important cause of WWI, was that many of these alliances were military in nature: that if one country attacked or was attacked, all of their allies had promised to get involved as well.


This meant that if just one country attacked another, most of Europe would immediately be at war, as each country jumped in to help out their friends. 


There were two major blocs of alliances that developed immediately before the war.


They were known as the Entente Powers and the Central Powers. The Entente Powers primarily consisted of France, Russia, and the United Kingdom.


In opposition were the Central Powers, which included Germany, Austria-Hungary, the Ottoman Empire, and Bulgaria.


Imperialism, as a concept, has been around for a very long time in human history. Imperialism is the desire to build an empire for your country.


This usually involved invading and taking land owned by someone else and adding it to your empire. 


By the 19th century, many European countries had been involved in imperialism by conquering less advanced nations in Asia, the Americas or Africa.

By 1900, the British Empire was the largest imperial power in the world. It controlled parts of five different continents and owned about a quarter of all land in the world.


France was also a large empire, with control over parts of south-east Asia and Africa.


By 1910, Germany had been trying to build its own empire to rival that of Britain and France and was looking for opportunities to expand.


This meant that when an opportunity for a war of conquest became available, Germany was very keen to take advantage of it.


Militarism is the belief that a country's army and navy (since air forces didn't exist at the start of WWI) were the primary means that nations resolved disagreement between each other.


As a result, countries like to boast about the power of their armed forces.

Some countries spent money improving their land armies, while others spent money on their navies.


Other countries tried to gain the advantage by having the greatest number of men in their armies, while others focused more on having the most advanced technology in their forces.


Regardless of how they approached it, countries used militarism as a way of gaining an edge on their opponents.

An example of this competition for a military edge can be seen in the race between Britain and Germany to have the most powerful navy.


Britain had recently developed a special ship known as a 'dreadnought’.


The Germans were so impressed by this, that they increased their government spending so that they also had some dreadnoughts.


The final of the four causes is 'nationalism'. Nationalism is the idea that people should have a deep love for their country, even to the extent that they are willing to die for it.


Throughout the 19th century, most countries had developed their own form of nationalism, where they encouraged a love of the nation in their citizens through the process of creating national flags and writing national anthems.


Children at schools were taught that their country was the best in the world and that should it ever be threatened, that they should be willing to take up arms to defend it.

The growing nationalist movements created strong animosity between countries that had a history of armed conflict.


A good example of this is the deep anger that existed between Germany and France.


These two countries had a recent history of war and struggling over a small region between the two, called Alsace-Lorraine.


The Franco-Prussian War of 1870-1871, which resulted in the German annexation of Alsace-Lorraine, created lasting animosity between France and Germany and contributed to the nationalist fervor leading up to World War I.


As a result, France believed that they should be willing to fight and die to take it back.


Finally, nationalism also involved ethnic nationalism, where smaller people groups sought to have their own nation-state, often at the expense of multi-ethnic empires like Austria-Hungary and the Ottoman Empire.

Conflicts and Crises

In the two decades before WWI started in 1914, there were a number of smaller conflicts and crises that had already threatened to turn into global conflicts.


While these didn't eventually start the global war, it does show the four causes mentioned above and how they interacted in the real world.


Also, these crises heightened tensions and mistrust among the great powers, only exacerbating the currently existing causes.

The Moroccan Crisis

In 1904, Morocco in north Africa had been given to France from Britain. However, the Moroccans had a growing sense of nationalism and wanted their independence.


In 1905, Germany announced that they would support Morocco if they wanted to fight for their freedom.


To avoid war, a conference was held which allowed France to keep Morocco. Then, in 1911, the Germans again argued for Morocco to fight against France.


France then gave the former French Congo to Germany to allow them to build an empire.

The Bosnian Crisis

In 1908, the nation of Austria-Hungary took control of the former Turkish region of Bosnia.


The country of Serbia was outraged, because they felt that it should have been given to them.


As a result, Serbia threatened attack Austria-Hungary.


To support them, Russia, which was allied to Serbia, prepared its armed forces.


Germany, however, which was allied to Austria-Hungary, also prepared its army and threaten to attack Russia.


Luckily, war was avoided because Russia backed down. However, there was some regional fighting during 1911 and 1912, as Turkey lost control of the region. 


Despite this, Serbia and Austria-Hungary were still angry with each other as they both wanted to expand into these newly liberated countries.

Further reading