Adams events show the fragility of peace and how easily it can fracture
It has been a bad week for the Northern peace process from almost everyone's point of view. It has starkly revealed its fragility, its susceptibility to pressure and the suddenness with which it can be propelled into spasm.
Allegations that Gerry Adams ordered one of the most shocking murders of the Troubles have, of course, been around for many years in books and TV programmes, and have often been put to him in media interviews.
He has always denied everything, and he has done so again under five days of police questioning.