Amnesty International estimates that about 250,000 children under the age of 18 are currently fighting in warzones. The practice is ancient and often highly secretive, but over the past couple of decades has been seared into the international consciousness, largely through graphic, wrenching images of young children in situations no child should ever experience. Wars in the Democratic Republic of the Congo and Liberia have become especially infamous for their use of child soldiers. Here a young rebel poses with his machine-gun in Kalemie, southeast Congo, on Sept. 2, 1998.
A Somali government soldier demonstrates to children how to use a Kalashnikov rifle in Mogadishu, on Sept. 13, 2009.
A teddy-bear-backpack-toting child soldier points his gun at a photographer in Monrovia, Liberia on June 27, 2003.
A child belonging to the United Liberation Movement of Liberia for Democracy takes a smoke break on Oct. 30, 1992, in Monrovia.
Young rebel fighters from the Liberians United for Reconciliation and Democracy militant group patrol Sept. 15, 2002, in Voinjama, Liberia.