Children in the military are children defined by the Convention on the Rights of the Child as persons under the age of 18 who are associated with military organisations, such as state armed forces and non-state armed groups.
Children are easy targets for military recruitment due to their greater susceptibility to influence compared to adults. Child recruits who survive armed conflict frequently suffer psychiatric illness, poor literacy and numeracy, and behavioural problems such as heightened aggressionleading to a high risk of poverty and unemployment in adulthood.
A number of treaties have sought to curb the participation of children in armed conflicts. According to Child Soldiers International these agreements have helped to reduce child recruitment,  but the practice remains widespread and children continue to participate in hostilities around the world.
History is filled with children who have been trained and used for combat, assigned to support roles such as porters or messengers, used as sex slaves, or recruited for tactical advantage as human shields or for political advantage in propaganda. Since the adoption in of the Optional Protocol on the involvement of children in armed conflict OPAC the global trend has been Legal age teenagers at army restricting armed forces recruitment to adults aged 18 or over, known as the Straight standard.
Nonetheless, Child Soldiers International reported in that children under the age of 18 were still being recruited and trained for military purposes in 46 countries;  of these, most recruit from age 17, fewer than 20 recruit from Legal age teenagers at army 16, and an unknown, smaller number, recruit younger children. These include non-state armed paramilitary organisationsusing children such as militiasinsurgentsterrorist organizationsguerrilla movementsideologically or religiously-driven groups, armed liberation movementsand other types of quasi-military organisation.
In the United Nations identified 14 countries where children were widely used by such groups: Not all armed groups use children and approximately 60 have entered agreements to reduce or end the practice since Singer of the Brookings Institution estimated that child soldiers participate in about three-quarters of ongoing conflicts.
Today, due to the widespread military use of children in areas where armed conflict and insecurity prevent access by UN officials and other third parties, it is difficult to estimate how many children are affected. Despite children's physical and psychological underdevelopment relative to adults, there are many reasons why state- and non-state military organisations seek them out.
While some children are forcibly recruited, deceived, or bribed into joining military organisations, others join of their own volition.
In a study of children in military organisations around the world, Rachel Brett and Irma Specht pointed to a complex of factors that incentivise enlisting, particularly:. The following testimony from a child recruited by the Cambodian armed forces in the s is typical of many children's motivations for joining up:.
I joined because my parents lacked food and I had no school I was worried about mines but what can we do—it's an order [to go to the front line ].
Once somebody stepped on a mine in front of me—he was wounded and died I was with the radio at the time, about 60 metres away. I was sitting in my hammock and saw him die I see young children in every unit I'm sure I'll be a soldier for at least a couple of more years.
If I stop being a soldier I won't have a job to do because I don't have any skills. I don't know what I'll do Since the Machel Report further research has shown that child recruits who survive armed conflict face a markedly elevated risk of debilitating psychiatric illness, poor Legal age teenagers at army and numeracy, and behavioural problems.
Further harm is caused when child recruits are detained by armed forces and groups, according to Human Rights Watch. Lawyers and relatives are frequently banned from any court hearing. Other research has found that the enlistment of children, including older children, has a detrimental impact even when they are not used in armed conflict until they reach adulthood.