[3] As the world divided into the Eastern (communist) and Western (capitalist) Blocs, a struggle for ideological geopolitical supremacy between the US and USSR emerged.

[7] While the doctrine was never formally invoked,[5] the US supported Hussein of Jordan in 1957 against an alleged coup attempt and moved to prevent communism from spreading in Syria.

Kamal Jumblatt and Rashid Karami, Druze and Sunni leaders, respectively, condemned Chamoun's support for the doctrine as violating the National Pact.

US attempts to influence the election included approving the sending of $12.7 million in military or financial aid and sending operatives from the Central Intelligence Agency (including David Atlee Phillips, Miles Copeland Jr. and Wilbur Eveland) to the region, who provided "campaign contributions" towards pro-West politicians.

[14] In late May 1957 pro-Chamoun troops killed seven and wounded seventy-three protesters in Beirut and the following month opposition leaders argued that Chamoun "had bought so many votes and gerrymandered so many districts that the balloting would be meaningless."

[18][19] The United States feared initially that the new nation would become the dominant power in the Middle East, but recognized it on 25 February after deciding that the UAR could be beneficial in halting communism's spread and keeping Nasser contained.

Although Chamoun's term would have expired on 23 September 1958, he intended to run for president again, which was not permitted in the Constitution of Lebanon, and asked for American support in his effort.

Robert M. McClintock, American ambassador to Lebanon, described Chehab as "a neutral legume who would require careful pruning to grow in the right direction.

Heightened tensions existed around the country, including in the Beqaa Valley, where Shia militants were receiving weapons from Syria.

[28] Chamoun requested American military intervention in early May against the threat to his power under the Eisenhower Doctrine, although McClintock noted that there was an "absence of overt Communist aggression".

[30] The UNSC passed a resolution on 11 June 1958 that recommended sending a group to Lebanon "to ensure that there is no illegal infiltration of personnel or supply of arms or other material across the Lebanese borders".

The goal of the operation was to bolster Chamoun's pro-Western Lebanese government from internal opposition and threats from Syria and Egypt.

At the end of June, Essex and Boston were anchored at Piraeus, Greece, while Des Moines, from which Vice Admiral Charles R. Brown was flying his flag, was at Villefranche-sur-Mer, France.

[36] On 16 July 1958, Admiral James L. Holloway Jr., CINCNELM and CINCSPECCOMME, flew in from London to Beirut airport and boarded USS Taconic from which he commanded the remainder of the operation.

Murphy played a significant role in convincing both sides of the conflict to reach a compromise by electing the moderate Christian general Fouad Chehab as incoming president, but allowing Chamoun to continue in power until the end of his term, on 22 September.