Eisenhower sent 15,000 Marines and soldiers to Lebanon

Eisenhower applied the doctrine in 1957–58 by dispensing economic aid to shore up the Kingdom of Jordan, and by encouraging Syria's neighbors to consider military operations against it. More dramatically, in July 1958, he sent 15,000 Marines and soldiers to Lebanon as part of Operation Blue Bat, a non-combat peace-keeping mission to stabilize the pro-Western government and to prevent a radical revolution from sweeping over that country.