Marine Security Guards for the U.S. Embassy in Belgrade, Serbia Lance Aaron Johnston and Gunnery Sgt. Laureano Perez lay a wreath at the Halyard Mission memorial in Pranjanje, Serbia, Aug 15, 2009 during the 65th annivesary of the Halyard mission. - Marine Security Guards for the U.S. Embassy in Belgrade, Serbia Lance Aaron Johnston and Gunnery Sgt. Laureano Perez lay a wreath at the Halyard Mission memorial in Pranjanje, Serbia, Aug 15, 2009 during the 65th annivesary of the Halyard mission.