IRA disarmament: Rubicon crossed?

Rosie Cowan believes the ball is in the Sinn Fein court. It is not going to be easy for them to play, but that it may be the logical destination for the generations old organisation:

“No one should under-estimate the monumental scale of the concept of disbanding the IRA for republicans: decommissioning was a huge issue, but the Provisional organisation itself has been an integral part of their identity and their everyday lives for generations. But some think the Rubicon was crossed the day Sinn Fein agreed to take its seats beside unionists in a Belfast parliament.”