In response to the power vacuum in the Middle East following the Suez Crisis, the Eisenhower administration developed a new policy designed to stabilize the region against Soviet threats or internal turmoil. Given the collapse of British prestige and the rise of Soviet interest in the region, the president informed Congress on January 5, 1957, that it was essential for the U.S. to accept new responsibilities for the security of the Middle East. Under the policy, known as the Eisenhower Doctrine, any Middle Eastern country could request American economic assistance or aid from U.S. military forces if it was being threatened by armed aggression. Eisenhower found it difficult to convince leading Arab states or Israel to endorse the doctrine, but he applied the new doctrine by dispensing economic aid to shore up the Kingdom of Jordan, encouraging Syria's neighbors to consider military operations against it, and sending U.S. troops into Lebanon to prevent a radical revolution from sweeping over that country. The troops sent to Lebanon never saw any fighting, but the deployment marked the only time during Eisenhower's presidency when U.S. troops were sent abroad into a potential combat situation.