How did imperialist nations expand and protect their interests around the world?

Militarism--the act of building a large military to protect land holdings. 

Industrial power led to new technological advances that also impacted military advances. To protect new imperial lands, European countries used their new modern military to obtain land and to defend it. 

Great Britain held the largest military in the world until after World War II. This military capability allowed them to hold a huge imperial empire which was protected by their navy and army. Great Britain even trained people in their colonies to be internal soldiers which increased their power around the world.