What predictors of war were in place before fighting began?

According to historical facts, the following are the predictors of wars:

1. Conflict history - This refers to arm conflicts between two parties that have occurred in the past. 

2. Clustered neighbourhoods and regions - Existing poverty and detrimental economic effects that could contaminate the regions are some of the risk factors considered in war prediction.

3. Population - Greater population are associated with increased conflict risk. 

4. Education - Lower risk of conflict is related to higher levels of primary enrollment, secondary male enrollment, greater education expenditure and higher literacy rate.

5. Infant mortality has said to have very strong effects on state failure and arm conflicts.

7. Characteristics of neighbouring countries - Countries that are situated in the poor neighbourhood have a higher risk of conflicts than those that are situated in more developed regions.

8.  Primary commodities, such as oil are linked to higher risk of conflict.

I believe the answer is: European countries amplified the size of their military's fleets and weaponry.
Amplifying size of the military would reduce the Gross Domestic Product that a nation have from other sectors. This means that the next course of actions of that country would most likely be an invasion toward another country to make up for the GDP that they lost.