The 1975 IRA-British truce is often viewed as the event that began the challenge to the original Provisional Sinn Féin leadership, which was dominated by southerners like Ó Brádaigh and Ó Conaill.
One of the reasons that the Provisional IRA and Provisional Sinn Féin were founded, in December 1969 and January 1970, respectively, was that people like Ó Brádaigh, O'Connell and McKee opposed participation in constitutional politics.