Vatta's War is a science fiction series by American writer Elizabeth Moon, comprising five books: Trading in Danger (2003), Marque and Reprisal (2004) (Moving Target in UK and Australia), Engaging the Enemy (2006), Command Decision (2007), and Victory Conditions (2008). They have been characterized as military science fiction similar in style to the works of Lois McMaster Bujold (Vorkosigan Saga), David Weber and Walter Jon Williams (Dread Empire's Fall).