The reasons for this heightened susceptibility are easily discerned. A normal part of military service involves being sent away from home for long periods of time. Troops and officers alike are often in search of recreation to relieve loneliness and stress, and many soldiers on deployment regularly have sexual contacts with prostitutes and the local population. For example, 45 percent of Dutch navy and marine personnel on peacekeeping duty in Cambodia had sexual contact with prostitutes or other members of the local population during a five-month tour. In a population-based survey of over 18,000 U.S. soldiers, 35 percent reported having one-night-stand sexual encounters in the previous 12 months. In another survey in 1995, 42 percent of 1,377 U.S. rapid deployment personnel reported having more than one regular partner and/or at least one casual partner during the preceding year. The risks of this sexual behavior are demonstrated by studies which reported that 10 percent of American naval personnel and marines contracted a new STD during trips to South America, West Africa, and the Mediterranean between 1989 and 1991.