Militarism - Great Britain and Germany both greatly increased their navies in this time period. Further, in Germany and Russia particularly, the military began to have a greater influence on public policy. This increase in militarism helped push the countries involved to war.
Alliances - Over time, countries throughout Europe made mutual defense argreements that would pull them into battle. Thus, is one country was attacked, allied countries were bound to defend them.
Imperialism - When a country increases their power and wealth by bringing additional territories under their control.
If we have more power, we will win this fight!
Nationalism - Loyalty to one's nation. A nation is group of people that share a common history, homeland , and want their own country.