Couple of direct examples:
- 34 US sailors die on USS Liberty June 8, 1967 when attached by Israeli fighter jets in the Sinai Peninsula
- 241 US service members (mostly Marines) on October 23, 2008 while on peace keeping mission in Beirut, Lebanon when a bomber blew up their compound. Israel invaded Lebanon in 1982, hoping to crush the PLO. In exchange for an Israeli withdrawal, the U.N. sent in a peacekeeping force made up of troops from Great Britain, France, Italy and the United States.
Most dramatic indirect example of course is 9/11, when US support for Israel against Palestine was cited as a main cause for the attack. 2,977 fatalities.