This, coupled with the increasing strength of the Syrian Communist Party,[citation needed] led to the establishment of the United Arab Republic (UAR), a union of Egypt and Syria, in 1958.

As relations between the two factions deteriorated, the Military Committee initiated the 1966 Syrian coup d'état, which ousted the National Command led by al-Razzāz, ʿAflaq, and their supporters.

[11] Its new, strengthened position was used successfully to garner support for Syria's merger with Gamal Abdel Nasser's Egypt, which led to the establishment of the United Arab Republic (UAR) in 1958.

[18] The Iraqi Ba'athists supported Qasim on the grounds that they believed he would enter Iraq into the UAR, enlarging the Arab nationalist republic.

[19] Qasim was overthrown in the Ramadan Revolution led by young Ba'athist officer Ahmed Hassan al-Bakr; long suspected to be supported by the American Central Intelligence Agency (CIA),[20][21] however pertinent contemporary documents relating to the CIA's operations in Iraq have remained classified by the U.S. government,[22][23] although the Iraqi Ba'athists are documented to have maintained supportive relationships with U.S. officials before, during, and after the coup.

[32] The Marxist wing gained new ground at the 6th National Congress (held in October 1963), in which the Iraqi and Syrian regional branches called for the establishment of "socialist planning",[33] "collective farms run by peasants", "workers' democratic control of the means of production", and other demands reflecting a certain emulation of Soviet-style socialism.

[36] On 23 February 1966, a coup d'état led by Salah Jadid, the informal head of the Military Committee, overthrew Aflaq and Bitar's cabinet.

[41] For more than 2 decades, Michel Aflaq's essay compilation titled "Fi Sabil al-Ba'ath" (translation: "The Road to Renaissance") was the primary ideological book of the Ba'ath party.

[53] The "Transitional Ba'ath", which grew out of the dissolution of the Syrian Regional Branch (1958) and the Military Committee, was more rural in outlook, policy and ideology.

[62] A third group, led by people disenchanted with both Nasser and the union period, remained in the Ba'ath Party but stopped believing in the feasibility of pan-Arabism.

[66] While he didn't oppose the pan-Arab project, he wanted to turn the concept of Arab socialism into a scientific and revolutionary socialist ideology which adapted Marxism to local conditions.

[75] Major policies in the "Arab road to socialism" included: The nationalization of the major branches of the economy with the participation of the toiling masses in the management of the economy, and for the creation of collective farms to effect the revolution necessary for the peasants...the Congress stipulated that the changes be directed by a "revolutionary vanguard", the final aim being to establish a "popular democracy" that was to guarantee freedom to the classes which constitute the true people and ensure the country's rapid development.

[77] The manifesto also stated that this envisaged Ba'athist generation would be "committed to scientific thought freed from the shackles of superstition and backward customs" and replace religion with Arab nationalism as their belief system.

[78] Neo-Ba'athism refers to the dramatic changes that manifested in Ba'athist ideology from 1960 to 1964, and the Military Committee's takeover of the Syrian Regional Branch and the National Command in the period 1964 to 1966.

[90] The party initially consisted of a majority of Shia Muslims, as Rikabi recruited supporters mainly from his friends and family, but slowly became Sunni dominated.

[94] The Iraqi Regional Branch supported Abd al-Karim Qasim's rule on the grounds that he would seek Iraq's entry into the United Arab Republic.

[95] Due to his policy reversal, the Regional Branch gathered a group, led by Saddam Hussein, which tried but failed to assassinate Qasim.

[99] After taking power, the Regional Branch through its militia, the National Guard, initiated what Iraqi expert Con Coughlin referred to as an "orgy of violence" against communist and left-wing elements.

[98] These repressive measures coupled with factionalism within the Regional Branch led to the November 1963 Iraqi coup d'état by President Arif and his Nasserite supporters.

[100] Iraq expert Malik Mufti believes Aflaq may have supported Arif's coup because it weakened al-Sadi's position within the party and strengthened his own.

[103] While the Regional Branch was not formed until 1951, several meetings took place at the universities where students and professors alike would discuss the Ba'athist thought.

[106] However, the Regional Branch leaders Rimawi, Na'was, Gharbiyah and Munif al-Razzaz opposed such an idea, and because of it, Shuqyar left the Ba'ath Party.

[28] A resolution was approved, which stated that the party leaders (Aflaq and al-Bitar among others) had too hastily entered into a union with Egypt, had wrongly dissolved the Syrian Regional Branch in 1958, and had given pan-Arabism primacy when socialism was more important.

[119] The growth of these pan-Arab ideologies concerned the government, which led to the incarceration of several Nasserist and Ba'athist military officers in the early sixties.

[120] The Ba'athist were accused of working to overthrow "the political, economic and social system" of the Kingdom; the sentences ranged from everything to eight months to two years.

The Ba'ath, now a large and popular organisation, won 15 out of 142 parliamentary seats in the Syrian election that year, becoming the second-largest party in parliament.

[124] The Ba'ath faced considerable competition from ideological competitors, notably the Syrian Social Nationalist Party (SSNP), which supported the establishment of a Greater Syria.

[128] Sixteen prominent politicians signed a statement supporting the coup, among them al-Hawrani and Salah al-Din al-Bitar (who later retracted his signature).

[131] Following the success of the Ramadan Revolution, led by the Ba'ath Party's Iraqi Regional Branch, the Military Committee hastily convened to hatch a coup against Nazim al-Kudsi's presidency.

[132] The plotters first order was to establish the National Council for the Revolutionary Command (NCRC), consisting entirely of Ba'athists and Nasserists, and controlled by military personnel rather than civilians from the very beginning.