Militarism: the belief or desire of a government or people that a country should maintain a strong military capability and be prepared to use it aggressively to defend or promote national interests. And the European powers at the time began building up in military power. This included the countries of Britain, France, Germany, Russia, and Austria-Hungary. The reason for the military buildup was primarily nationalism in which each country wanted to be "better" than the others.
I learned about this in French class! July 14 is Bastille Day in France (essentially like an independence day) because on that day, the French people stormed the Bastille prison. Hope this helps!