Last year, the U.S. Army in Afghanistan has removed the prohibition on sex between male and female soldiers. There are 68,000 U.S. troops in Afghanistan, and about ten percent of them are female. So far this year, about fifteen percent of these female troops have had pregnancy tests, and a few percent of the female troops have gone home because they were pregnant.
Since the 1990s, the army has been big on clean living (or whatever you want to call it) in combat zones. No booze, no sex and not cavorting (you know what that means) with the locals. But with most of the troops in combat zones being young and single, things happened. Some couples got caught. Commanders got tired of having to punish (usually with an Article 15, which is just short of a court martial) troops for "unauthorized fornication." So now it is, if not authorized, not likely to get you punished (aside from the occasional unexpected pregnancy).