Answer:
New Imperialism
Explanation:
What fueled the conflicts among the European nations in the 1900s is "NEW IMPERIALISM"
In their bid to colonize some specific territories that are believed to have high natural resources that can serve their interest, many of these European countries, particularly the powerful ones among them, had so many conflicts among each other on which territory to claim as their subject.
This conflict is one of the reasons Franz Ferdinand was assassinated which eventually led to World War 1.