I thought it noteworthy that an unnamed Pentagon source claims that “an Army brigade” has been put on alert for Lebanon:
Around 5,200 American troops are based in Iraq to train Iraqi forces and help in the fight against Islamic State group militants. Defense officials who discussed the new troop movements spoke on condition of anonymity to discuss a decision not yet announced by the Pentagon. A Pentagon official who was not authorized to be identified said the U.S. also had placed an Army brigade on alert to fly into Lebanon to protect the American Embassy. U.S. embassies also issued a security alert for Americans in Bahrain, Kuwait and Nigeria.