The question: Was the revolution a synthesis of Islamist and Leftist (by this I take "Marxist") revolutionary movements? Yes and no. The answer is "Yes" in that the the Iranian revolution in many sense matched the descriptive Marxist vision for how a revolution ought to occur, but that said revolution was under the leadership of clerical (and ultimately reactionary) Islamism as opposed to revolutionary communist parties. The answer is "No" in that there was no conscious attempt at ideological or political synthesis by the leadership of the Iranian revolution between Islamism and Marxism. I suppose the best way of outlining this is going through the essential facts of the revolution itself and trying to understand the different and shifting positions of political and social forces.

The Iranian revolution was, in essence, a revolution of the urban working class, which led the rural peasantry. It was marked by working class uprisings in the cities with mass mobilisations, general strikes, and ultimately the de facto seizure of power by soviets - shoras in the Iranian context - which had secured control of the key sectors of the economy.

However, the main political leadership was always under the influence of Islamism. This should be qualified - there were prominent Marxist and even "Islamic-Marxist" trends in the Iranian revolution. The Fedaian and People's Mujhadeen (MEK) were all at least nominally communist and Islamist, and were seeking to overthrow the Iranian government through guerilla tactics along the lines of Che Guevara's Foco theory or Mao's theory of people's war, and these trends ultimately delivered the coup de grace to the dictatorship through pitched street battles with the government, ultimately leading to the capitulation of the Iranian military to the revolutionaries.

The Fedaian and MEK groups (and in this I am including their splits and offshoots) were generally anti-clerical despite their Islamist influences, and some would outright reject Islamism together, fully embracing some variant of Marxism-Leninism or Maoism. There was a small Trotskyist group, the Socialist Workers' Party, but it was not relevant and was repressed by the revolutionary government. In addition, there was the Tudeh party, the Soviet-backed "Official" Communist party which was quite small in this period, as it had never recovered from the severe repression against it carried out by the Western-backed Shah dictatorship after the overthrowal of the Mossadegh government in 1953. Nonetheless, it was influential, with members and supporters throughout the armed forces and state apparatus, as well as Soviet backing.

Despite the variety of ideological positions, all supported the revolutionary process and the overthrowing of the dictatorship, and most were willing to engage in what effectively amounted to a "cross-class alliance" between the revolutionary working class and the anti-imperialist national bourgeoisie of Iran, led by the Khomeini.

However, this was mostly one-sided and Khomeini did not have any real desire to align himself with "atheistic Marxists". Khomeini was in discussions with the Carter administration, with the US Ambassador to Iran encouraging NATO and pressuring the US-influenced Iranian military to effectively work exclusively with the Khomeini-led opposition. Khomeini's relations to the US were viewed in his eyes as a means to counteract the influence of communism in Iran, which was a key issue for him going back to the early 60s. That said, there is some controversy around how committed the US was to either backing the Shah or allowing Khomeini to come to power for their own reasons. The Constituent Assembly elections were marked by massive voter suppression which depressed any potential working class turnout in support of left wing parties, and paramilitaries in support of Khomeini regularly attacked and killed left wing activists.

That all said, as things developed more sections of the revolutionary left moved into opposition to Khomeini. The Fedaian was already split between the more Islamist majority and a more hardline Marxist-Leninist minority (which rejected the Soviet Union as "revisionist"), with the minority opposing the Islamists. In addition, the Islamist-influenced MEK had moved into opposition due to the clericalism of the Khomeini-led opposition. The Fedaian (Majority) still backed Khomeini, as did the Moscow-line Tudeh.

Things took a turn for the worse after the Khomeini regime engaged in a parliamentary coup d'état against the more anti-clerical wings of the government and began establishing its theocratic dictatorship. In response to protests against the coup, led by the MEK, the new Khomeini regime began a campaign of mass repression against the left of all stripes, including those sections that supported it, with mass purges from the state institutions, mass arrests, and ultimately mass executions. By 1982, there was huge dissent in Tudeh at the turn of events and it was moving towards opposition. In order to head off the possibility of a communist opposition cohering itself, the CIA and MI6 collaborated with the Khomeini regime, selling it arms and feeding it information on Tudeh activists, which they in turn received from a KGB defector. Roughly ten thousand Tudeh activists were rounded up and most were later executed. By 1983, Tudeh leaders were all imprisoned and Iran was a one-party state. To add insult to injury, Tudeh leaders were forced regularly to appear on TV to effectively denounce communism and praise Islam. Those who refused were tortured to death.

The invasion by Saddam's Baathist government in Iraq in 1980 complicated the situation for the left. The invasion was explicitly counter-revolutionary in nature, attempting to contain the Iranian revolution for fear that it would influence the Shia population in Iraq. The subsequent war resulted in a consolidation of popular support around Khomeini at the expense of the left, and much of the Iranian left was confused as to what stance to take on the war - that is, whether or not to support Khomeini in the context of the war, or to continue to maintain political opposition. Ultimately, after the Khomeini moved towards outright destroying the left in 1981, some sections such as the MEK dramatically shifted position and began engaging in terror attacks against the Iranian government, and ultimately moved towards support for the Iraqi invasion (which it had previously fought against with its own armed forces in 1980), and in the late 1980s - by which point the Islamist regime was more or less completely consolidated in Iran - it was joining the Iraqi army in multiple military operations including the use of chemical weapons. How "left wing" the MEK were at this point is very much up for debate.

If we examine the relationship between different political parties and leaders in the Iranian Revolution, it is quite hard to argue that a synthesis occurred. Rather, it was a series of conflicting and shifting political alliances and conflicts, with Khomeini not really ever having any intention of perpetual coexistence. Even those on the revolutionary left who were the most supportive politically or closest ideologically to Khomeini were either betrayed by him or moved into opposition to his regime, and despite his anti-imperialist rhetoric, Khomeini was more than happy to take the help of the "Great Satan" when it came to smashing communism, a goal which they both shared.

Stepping back from the "palace intrigue" a bit and looking more at what the masses were doing, the case for "synthesis" is much stronger. The shoras in particular should be of interest to us, as they were the most direct expression of working class power in the revolution and were tools for workers' control and self-management, but were very much of an Islamist providence and were effectively a local variation of what the Marxist perspective of the need to establish soviets, dual power, and so on, and how such institutions arise organically in periods of working class revolution. The shoras were predominantly organisations of workers which organised key sectors of the economy, and oil workers in particular established the most influential shoras. Once the Shah was overthrown, the shoras immediately ran into conflict with the new government which sought to restore the status quo in labour relations, and the shoras became a battleground between Islamists and the left with the former wanting to turn them to support for the new Islamist regime and the latter largely wanting to turn them away from that. Ultimately, the shoras were dismantled by the Islamist government not long after the Shah dictatorship was toppled.

So, was the Iranian revolution a synthesis of left wing revolutionary and Islamist anti-imperialist movements? There is a case to be made but, in my opinion, ultimately no. The revolution - like most revolutions - was one of competing alliances, social forces and interests. That said, it very much took on many characteristics of a communist revolution, but without the communist ideological leadership. Rather than a genuine synthesis, this enabled the Islamist forces to capitalise on the anti-Shah struggle of the masses and secure power at the expense of the existing left wing forces in Iran at that period in time.