Following factors were responsible for the First World War:

Frankfurt Treaty: It was a peace treaty signed in Frankfurt on 10 May 1871, at the end of the Franco-Prussian war In this war, Germany (Poussia) had defeated France and compelled France to sign the Frankfurt Treaty.

• According to which France had to pay a war fine as well as give away two of its provinces Lorraine and Alsace to Germany.
• France had not been able to overcome this humiliation.
• Thus, Frankfurt Treaty itself was the cause of the First World War.

Economic Factors:

England had established its vast empire in Asia and Africa in the 19th century by exploiting its colonies economically.

1. Due to industrialization and colonisation, Europe required huge Quantity or raw material.
2. In the last Quarter of 19th century, Germany had started the competition to produce the markets in Asia and Africa.
3. It started supplying cheaper goods in comparison to England and France.
4. It broke up the market of England and France.
5. Thus, there was an intense economic competition between Germany and England.

Militarism: 

Military force was necessary and important for the competition that the European nations got into for expansion.

1. England, France, Austria, Russia, etc., had begun expending their military power.
2. Countries like Japan, Italy and Germany, compulsory military training had started.
3. Production of weapons was increased under the pretext of self-defence.
4. Thus, militarism got an impetus and military competition added to economic competition created a serious atmosphere of war.

Groupism-Secret Treaties:

Groupism and Secret treaties played a major role in the First World War.

• The world was divided into two groups before the First World War.
• On one side was the group of Germany, Austria, Hungary, Bulgaria and Turkey while on the other side was the group of England, France, Russia and Japan.
• A feeling of jealousy, enmity, mistrust, fear and hatred evolved between the groups which was an important factor of the First World War.

Feeling of Fierce Nationalism:

1. The independence of Belgium and Greece and the unification of Germany and Italy were the result of nationalism.

2. The feeling of nationalism took an extreme and narrow from in Europe.
3. Economic jealousies, competitions and colonialism in Europe had increased so much that the national interest of each other began to clash.
4. Leading European nations began teaching extreme and destructive nationalism to its people.
5. Love for own nation and hatred or the other nations was encouraged.
6. The German Chief Kaiser Wilhelm wanted to get things done according to his will with the help of his grand military power.
7. The feeling of war spread across other nations.

Role of Newspapers

 The newspapers of the European nations around so much of hatred among people with their mutual, derogatory, provocative, exaggerated and false write-ups by spitting venom against rival nations that the rulers of the respective nations could not even make efforts for establishing peace and harmony.

1. Philosophy about war: The policy of “War is Warfare” took root in Europe.
2. Trotsky published maxims like “only one mighty deserve to live” and “War alone is the national need”.
3. Nietzsche, the German writer expressed war as “a sacred work”.

Immediate cause

The Prince of Austria and his wife were assassinated by being shot at by a member of the Serbian terrorist organization “Black Hand”, Austria blamed Serbia for the involvement in the act and gave an ultimatum to hand over the culprit to Austria within 48 hours.

• Serbia declared its ignorance in the matter.
• Thus, Austria declared war on Serbia and the First World War had begun on 1st August 1914.