The Soviets supported the Official IRA initially. However, the OIRA was heavily criticised by its Catholic Nationalist base after the outbreak of violence in the summer of 1969 for not adequately protecting Catholic estates during unionist riots, RUC repression, and violent pogroms that drove thousands from their homes. At this point, the OIRA examined the conflict through an almost purely Marxist lens and sought to build a workers movement in the North of Ireland that tried to foster unity between Nationalists and Unionists. However, most Nationalists, and indeed, many of the IRA's own rank and file, denied this analysis after violence against Catholics started up, and especially rebuked the meek and lackadaisical approach of the OIRA's leadership for not defending these communities with arms.

By the end of 1969, at the IRA's general meeting (ard-fheis), a separatist movement spurred by more traditionalist members started that led to a formal split in the organisation, and the creation of the Provisional IRA. The PIRA, while still socialist, was much more nationally focused as an organisation and did not go out of its way to craft strong relations with the socialist world like the Soviet Union and its allies. A notable exception is that PIRA's political wing Sinn Féin crafted an exceptionally strong relationship to the Cuban government, which it still has today. Another is the support from Muammar Gaddafi's Islamic socialist government in Libya that procured vast amounts of heavy arms for the PIRA.

The PIRA quickly eclipsed the OIRA in membership and general support. By the early 70s, PIRA was several times larger than OIRA. By 1972, OIRA gave up its short armed campaign altogether, and effectively stopped being a major force in the conflict.

While the Soviets had a line of support to the Officials in their quest to build a united socialist Irish state under Marxist principles in the spirit of James Connolly, it did not have the support base necessary to stay a major force in the conflict. The Soviets would never come out in strong support of PIRA, which would remain the dominant Nationalist paramilitary for the entirety of the conflict.