The Taoiseach has said he believes the gun has been removed from Irish politics.
Speaking to RTÉ today, the Taoiseach said he believed the gun had gone out of politics but warned that any return to war would leave the Republican movement firmly out in the cold.
Mr Ahern insisted the public would judge Sinn Fein's sincerity and credibility over the coming months and assess whether they were fit to be in the democratic fold.
Mr Ahern also repeated his assertion that there was no hope of a Fianna Fáil/Sinn Féin coalition government following the next general election.
"How could I sincerely negotiate something with Sinn Féin that would get me elected Taoiseach and then think that I would run it for five years. I mean because there are so many differences in our policies I could hardly get through five days," he said.
"You have to be honest, it wouldn't work.
"It doesn't just apply where Sinn Féin go, that equally you couldn't in my view have a government of Fine Gael, Labour and the Greens because they wouldn't agree on the weather," he said.
Mr Ahern insisted that a deal to enable a return to power sharing in the North would happen.
"I totally and fully understand the concerns that the DUP have. I would share those but I think we are finding resolutions to the concerns," he said.
With the Independent Monitoring Commission report on IRA activity in January crucial to achieving a settlement, the Taoiseach said he hoped an agreement would be reached next year.
Mr Ahern refused to speculate on whether the so-called Colombia Three would be returned to south America to serve 17 years in jail for training FARC rebel guerillas.
Colombian authorities are pursuing an extradition order for Niall Connolly, Martin McCauley and James Monaghan but the Taoiseach refused to be drawn on the matter and said the rule of law had to run its course.
Mr Ahern said no deal had been done to release a four-man IRA gang jailed over the killing of Garda Jerry McCabe.
"That is out of the equation now for all of the reasons and all of the sensitivities that came up," he said.
The Taoiseach insisted the men jailed for manslaughter - Kevin Walsh, Pearse McAuley, Jeremiah Sheehy and Michael O'Neill - would not get early release. He said the gang would serve their sentences in full and that on-the-run IRA members wanted for the killing would not be given an amnesty.