A: There are not U.S. Marines at every embassy. U.S. Marines serve at 148 embassies and consulates, according to www.marines.mil, the official website of the U.S. Marine Corps. These Marines are part of the Marine Security Guard (MSG), whose primary mission is to "provide internal security at designated U.S. diplomatic and consular facilities in order to prevent the compromise of classified material vital to the national security of the United States," according to www.mcesg.marines.mil. Victoria Nuland, spokeswoman for the U.S. Department of State, said in a Sept. 13 press briefing that "there are embassies without Marines, there are other consulates of this type without Marines," such as the diplomatic mission in Benghazi, Libya, where U.S. Ambassador Chris Stevens and three other Americans were killed in the Sept. 11 attack. She added that decisions are based on local conditions and that external security is employed at times. She added: "It depends on the circumstances and it is different in every part of the world, and we evaluate it along with our friends at the Defense Department and other agencies individually, per mission." Stevens, 52, died after he and other embassy employees went to the consulate to evacuate staff under attack from a crowd firing machine guns and rocket-propelled grenades.