The Government's policy on neutrality has been sharply criticised by the Fine Gael leader.
Mr Enda Kenny said he believed that "Fianna Fáil and their reconstructed betters, the PDs" had done the State no service at all on the issue.
"In fact, I believe that the reductionism of the politics practised in the foreign policy area by both these parties insults the dignity and intelligence of the Irish electorate," he said.
"What's more, I believe this reduction of politics, exemplified by the grail that is the parish pump and all its limitless possibilities, has prevented Ireland from shaping its own destiny and, by extension, the destiny of Europe and the world."
Mr Kenny, who was addressing the Humbert School in Mayo, said it was his task to get Ireland to "come out" on neutrality, in the absence of any coherent leadership from Fianna Fáil and the PDs. "Fine Gael does not regret the end of neutrality," he said, "but we abhor the manner of its demise: unaddressed and by default."
Mr Kenny said it was clear that the time for Ireland's splendid isolation was over. "Our neutrality served us well in our infancy," he added, "but now that our statehood is mature, we can afford to do things differently."
He said that from the start Ireland's neutrality was defensive, defiant, even belligerent. The emergence of a common European defence gave Ireland an opportunity to look at what it might be able to do. "Like it or not, we are no longer neutral. We are unaligned."
He said the publication of the draft EU constitution made a common European security and defence policy inevitable, giving Ireland the unmissable opportunity to decide, as opposed to merely accept, what the arrangements for this would be.
The question was whether we accepted an architecture designed by others or did we become one of the architects ourselves.
"One of the most powerful economic, social and political unions in the world needs a common defence, especially now that terrorism is a global threat," said Mr Kenny.
"Certainly, no single European seat has the financial or military resources to respond alone to that threat. Our security, then, lies in recognising our interdependence and the mutuality of our obligation. After all, Europe is our continent. Right now, there is no logical reason why a terror cell targeting American interests overseas would not strike here."
