 For example, in 2013 the average age of a United States Army soldier beginning initial training was 20.7 years.Historically, the use of children under the age of 18 for military purposes has been widespread – see Children in the military – but has been in decline in the 21st century.According to Child Soldiers International, as of 2017 approximately two-thirds of states worldwide had committed to restrict military recruitment to adults, while 50 states were still recruiting personnel aged 16 or 17, including most of the world's major military powers.