How did the 3 isms create tension in Europe in the early 1900s?

Imperialism- The need for countries to expand their influence.

Militarism- Countries wanting to build up their militaries, placing importance in them.

Nationalism- Placing importance in country, believing the country is the best.

Nationalism made all of the involved countries believe they were the best; excessive national pride. Militarism had them place great importance in the military, which caused many countries to build very large militaries (and the want to use them). Imperialism made these countries want to expand their influence.

In other Words, powerful countries expanded influence until they began to clash with each other. Because they had excessive pride and large militaries, they were more than happy to resort to violence in order to solve their differences.