As I understand it, the stumbling block is that the Good Friday agreement has enough wiggle room that the IRA can argue that putting their weapons "beyond use" is equivalent to "decommissioning" them, while the the Unionists believe the agreement says that the IRA has to give up or destroy their weapons. Trimble resigned as leader of the Unionists a few months ago because the IRA was still trying to find ways to weasle out of giving up their weapons. Recently Gerry Adams tried to finess the difference with his proposal, but it was rejected by the Unionists.

A BBC story about the argument is [link|http://news.bbc.co.uk/hi/english/static/northern_ireland/understanding/themes/decommissioning.stm|here]. The impression I've gotten is that the IRA is being the troublemaker in this disagreement.

Cheers,
Scott.