Chairman of the Joint Chiefs of Staff Gen. Martin Dempsey is in Israel to oversee the Austere Challenge joint military exercise. The drill – which brings together Israeli soldiers with 3,000 American troops spread across Israel, Europe, and the United States – simulates missile attacks on Israeli cities and tests joint U.S.-Israeli missile defense capabilities. It is the largest such exercise of its kind and will end with a live-fire interception of an incoming missile by a Patriot air defense battery. The trip is Dempsey’s second to Israel in 2012.