Rejection of the Treaty of Nice would send a "valuable warning message" to Irish and European Union policy-makers about the largely secret development of defence and security policies and structures, a conference in Dublin was told at the weekend.
Mr Andy Storey of AfrI (Action from Ireland), a Dublin-based group which campaigns on social and political issues, said it was not sustainable for the Taoiseach, Mr Ahern, to claim that "the security and defence aspects of the treaty are minor technical details".
Speaking at an organising conference of PANA (Peace and Neutrality Alliance), which is co-ordinating much of the campaign for a No vote, Mr Storey highlighted Irish involvement in the EU's Political and Security Committee, which is given a role under the treaty in the "political control and strategic direction" of joint crisis management operations carried out by the member-states.
"A representative of the Irish Department of Foreign Affairs sits on the EU Political and Security Committee, responsible for day-to-day co-ordination of the Common Foreign and Security Policy; this committee is given advice by an EU military committee, on which an Irish army officer sits as the representative of the Irish chief of staff."
Ireland had pledged 850 soldiers to the new European Rapid Reaction Force (ERRF) of 60,000 troops which would implement the Peterberg Tasks, namely, humanitarian and rescue missions, peacekeeping and crisis management, including peacemaking.
While Ireland could, in theory, opt out of any proposed action on a case-by-case basis, Mr Storey claimed that "in practice, the level of choice is likely to be limited".
Operations would have to be planned well in advance and troops committed accordingly.
"It will be very difficult for an individual state (such as Ireland) to backtrack on its commitment, whatever reservations might subsequently emerge, assuming that Irish representatives would be willing to entertain and express such reservations."
In addition, the Peterberg Tasks "may sound soothing, but they actually constitute a very wide agenda for action".
The definition of a humanitarian task or of peacemaking was "by no means clear-cut". He noted that the NATO bombing of the former republic of Yugoslavia had been grotesquely described as a "humanitarian intervention" at the time.
There had been Government assurances that Irish troops would participate only in ERRF operations which had a United Nations mandate, "but a UN mandate has itself become an elastic concept. The sanctions imposed on the Iraqi people, and which cause the death of 5,000 children a month, are mandated by the UN, manipulated as it is by the United States in particular."