It's not hard to see why Sinn Féin wants to turn up the volume on Irish unity. The recent agreement on police and justice devolution from Westminster to Belfast set the seal on a 15-year process that has brought the republican leadership into the heart of the power structure in Northern Ireland. To this structure it has delivered far-reaching reforms, the withdrawal of troops and once unthinkable advances in civil rights and equality.

But to many of Sinn Féin's supporters, the central goal of Irish republicanism – the end of British rule in the north and the reunification of Ireland – looks as far away as ever. That fuels the armed dissident republican campaign, however politically marginal it looks likely to remain. As one Sinn Féin leader put it to the packed February London conference on Irish unity, the Good Friday agreement was an "accommodation, not a settlement" and "the underlying cause of conflict persists". Read Seumas Milne's full article in the Guardian...