Causes of WWI
Industrialization
The manufacturing method was changed by the Industrial Revolution, which made mass production of weapons simpler and faster. As a result, the major countries engaged in an arms race as they aimed to retain or boost their military might by bolstering their armies and fleets.
Industrialization is known as the transition from predominantly agricultural to mass-produced, technologically advanced goods and services 
This leads to an rise in economic competition across European Nations
Nationalism
Nationalism is the ambition to unite all citizens of a country under one government
How it led to WWI 
 Nationalism led to the outbreak of World War One  as a result of nations' desire to position themselves as the most powerful and developed society on the world.
Militarism 
Militarism is the ambition of a nation to bolster its military forces in order to increase its power.
When large armies were built up, it created lots of tension throughout countries, notably Germany and Russia. This tension pushed the countries to be involved in war and test which countries have the best armies. 
In this photo you can see the large armies built
Imperialism
This photo shows how the strong country, England, has its arms on all the other countries. 
The expansion of empires by nations like Britain and France contributed to rising tensions among the European nations.
Imperialism is a political system or a desire for dominance and power over other nations that involves a wealthy, strong country.
Alliances
How it led to WWI
When one country gets threatened, the countries they have alliances will come to help, this has a potential to escalate the conflicts 
There were 2 main groups of alliances in WWI 
Central Powers 
Germany
Austria - Hungary 
Ottoman Empire 
Bulgaria 
Italy (until 1955) 
The Triple Entente
France
Great Britain
Russia 
Italy (1915-)
U.S. (1917)
An alliance is a partnership between two or more people, groups, or nations that has been formed to further a shared goal.