In December of 1970, the Jordanian Communist Party (JCP) experienced its first major split. The nature of the split concerned the question of Palestine and armed struggle as the Palestine Liberation Organization (PLO) and its constituent revolutionary movements suffered a major and irreversible defeat at the hands of the Hashemite monarchy during what came to be known as Black September. The split was the culmination of a year-long factional struggle that emerged within the party over the political orientation of the party in times of fierce repression. Whereas the moderate line of Fahmi al-Salfiti advocated for accommodation with the Jordanian authorities, the revolutionary line of Fu’ad Nassar understood armed struggle to be the only means to overthrow reactionary, pro-imperialist Arab regimes. Accusing the accommodationist wing of being “petit bourgeois,” the Nassar faction of the JCP established a feda’i wing of the party called al-Ansar (the Partisans). Though al-Ansar also contained revolutionaries from the Iraqi, Lebanese, and Syrian Communist Parties that were committed to armed struggle for the liberation of Palestine, they were viewed by other Palestinian movements with heavy suspicion, and were never incorporated into the resistance. What were the main ideological tensions between the JCP and other Palestinian revolutionary formations? What implications did the tragic events of Black September have on the JCP in Jordan? How did the 1970 split affect future splits within the party? Utilizing primary sources published by these movements, as well as interviews and memoirs, this paper will answer these questions by revisiting significant 1960s ideological milestones. It will specifically focus on the ideological clashes between the accommodationist and the revolutionary wings of the JCP, as well as the role that the revolutionary wing played during Black September. Whereas most accounts of Black September focus on organizations affiliated with the PLO, this paper will shed new light on the political crisis within the JCP, historically the largest and most organized leftist party in Jordan. Beyond the JCP, similar crises took place in other major Jordanian parties. As this paper will argue, intra-factional clashes taking place across the Jordanian civic sphere signaled a major shift in the political and tactical orientation of a wide range of Jordanian parties towards both the Hashemite monarchy and the question of Palestine.