Yesterday President Obama issued blanket waivers allowing Yemen, Chad, and South Sudan to continue receiving US military aid despite their use of child soldiers. Via ThinkProgress:
The Child Soldiers Prevention Act of 2008 (CPSA) is meant to bar the United States from providing military assistance to countries who have “governmental armed forces or government- supported armed groups, including paramilitaries, militias, or civil defense forces, that recruit and use child soldiers.” As per the Optional Protocol on the Convention of the Rights of the Child, “child soldiers” include children under 18 who have been forced into service, those under 15 who have volunteered to fight, and and those under 18 who have joined up with any force aside from an army. It also includes those who serve in a “support role such as a cook, porter, messenger, medic, guard, or sex slave.”
A national security interest waiver was built into the law, however, giving the President the authority to override the law should he deem it necessary to do so.
If you read the whole piece, apparently there's a perverse diplomatic logic to this decision, but perverse logic isn't much to hang your hat on.