Starting in the 17th century, the American Colonies adopted a local militia system to which every able-bodied man between the ages of 18 and 45 was required to belong.

FORBES: Magazine Article

Neutral Switzerland requires every able-bodied man to serve in the army, starting with a five-month stint at age 19 or 20, with annual refresher courses lasting several weeks for the next 10 years, and more for officers.

BBC: Knives out for conscription into Swiss army