US marines
Media playback is unsupported on your device
Video

US marine: 'I am not worried about going to war'

Across the globe there are men and women fighting in many conflicts.

In the US, serving in the military is a way for young people to get a subsidized university education.

The BBC's Regan Morris went to San Diego to meet with an 18-year-old marine to ask him why he joined the military.

Go to next video: Pakistan's female fighter pilot