President Barack Obama has exempted four countries from a law that restricts the United States from providing military aid to governments that employ child soldiers, and a Republican congressman who co-wrote the law wants to know why.

A memorandum signed by Obama and released by the White House on Oct. 25 claims that the exemptions are due to “national interest.” The countries exempted are Sudan, Chad, Yemen, and the Democratic Republic of Congo.

Those four countries were named in a State Department report as “hosting governmental armed forces or government-supported armed groups that recruit and use child soldiers.” Two other nations named in the report -- Myanmar (Burma) and Somalia -- do not receive military aid from the United States.