Senators Dick Durbin (D-IL) and Sam Brownback (R-KS) introduced last week the Child Soldiers Prevention Act of 2007, a bill to prohibit the United States from providing financial support to nations in which children fight as soldiers. According to Senator Durbin, this bill addresses a widespread problem in many nations currently enjoying U.S. military aid. "Hundreds of thousands children around the world today are used as child soldiers,” said Durbin. “These boys and girls wield automatic weapons on the front lines of combat, serve as human mine detectors, participate in suicide missions, carry supplies, and act as spies, messengers or lookouts and sex slaves - endangering their health and lives and sacrificing their childhoods." Under the Durbin/Brownback bill, a child soldier is defined as any person under the age of 18 who takes part in hostilities or is conscripted into an armed force, or any person under the age of 16 who is recruited into a nation’s military.
Human Rights Watch has more on this issue at this link.