The conundrum at the heart of the Northern Ireland peace process was brought home to Liberal Democrats last night at a fringe meeting bringing together Sinn Fein and the loyalist Ulster Democratic Party.
Gary McMichael, leader of the UDP, said Sinn Fein's refusal to begin the process of decommissioning its arms was a "major obstacle" to progress. If Sinn Fein was committed to peace, as they said, why did their "alter ego", the IRA, think they needed weapons?
Mr McMichael's question was rhetorical. For though he and Mitchel McLaughlin, the chairman of Sinn Fein, broke new ground by sharing a platform, there was no dialogue. Nor were there any public handshakes.
Mr McLauglin said that 14 months after the IRA ceasefire no-one could be confident there would ever be peace talks. "Yet all parties are agreed on many of the essential principles - including the principle that all guns must be taken out of Irish politics forever."
The Sinn Fein chairman said his party wanted to be involved in inclusive political dialogue involving all of the people of the island of Ireland. Republicans wanted the consent, not the coercion of the Unionists for a united Ireland. "If the people of Ireland ... decide on an alternative, then that alternative, freely arrived at by the Irish people, is binding on all parties."
Mr Mclauglin said the reality of the trend in Northern Ireland was that four of the six counties had a nationalist majority. "There will eventually be a majority in all six."
Mr McMichael said no-one was "asking the IRA to surrender, merely to engage the process of decommissioning". Pressed on whether he would accept a vote for a united Ireland, he said: "If the people of Northern Ireland decide they want constitutional change, I, as a democratic politician, am bound to accept that."