Distinction between Sinn Féin and the IRA?

While describing the IRA offer to shoot the murderers of Robert McCartney as extraordinary and horrific, Taoiseach Bertie Ahern also says things have to move forward in the peace process and that there is a distinction between Sinn Féin and the IRA.

Is the Irish leader alone in this view or is Ahern merely saying this because he is worried that any criminalisation of Sinn Fein together with the IRA will be counterproductive to the long-term stability of this island?