 About 40% of the Bolivian army was believed to be under the age of 18, with half of those below the age of 16. , Bolivia invites children to begin their adult conscription early, from age 17.In Canada, people may join the reserve component of the Canadian Forces at age 16 with parental permission, and the regular component at 17 years of age, also with parental permission.They may not volunteer for a tour of duty until reaching age 18.