NEW : ` ` I think that today may in fact have been their first mission , '' Robert Gates says . NEW : Vice Joint Chiefs chair says drones help distinguish ` ` friend from foe '' NEW : Gadhafi loyalists ` ` nestle up in crowded areas , '' ' John Cartwright says . NEW : Air force , missile and radar sites , as well as helicopters , are prime targets .
NEW : `` I think that today may in fact have been their first mission , '' Robert Gates says . NEW : Vice Joint Chiefs chair says drones help distinguish `` friend from foe '' NEW : Gadhafi loyalists `` nestle up in crowded areas , '' Gen. James Cartwright says . NEW : Air defense , missile and radar sites , as well as troops , are authorized targets .