In letter , Jalal Talabani says detainee is civil servant on trade mission . Comment: Man was merely doing business in Kurdistan region , Talabani says . Iran threatens to close border , which would harm trade , he says .
In letter , Jalal Talabani says detainee is civil servant on trade mission . U.S. military says man belongs to elite unit that trains , equips insurgents . Man was merely doing business in Kurdistan region , Talabani says . Iran threatens to close border , which would harm trade , he says .