This far into the peace process, Sinn Fein needs to find a way - a believable way - of addressing the IRA question.

Republicans cannot, on the one hand, criticise the British government for not holding a public inquiry into the Pat Finucane murder, cannot demand so many truths from others while, at the same time, continuing with the IRA lie.

No one believes that Gerry Adams was never in the IRA, or that Martin McGuinness left the organisation in 1974.

And yes, there may well be reasons why both men still feel the need to be circumspect about what they say in terms of their precise roles within the IRA leadership at the level of the 'army council'. But being circumspect and insulting the intelligence of others are two different things.

Recently, I was on radio being interviewed about Gaddafi (below right) and the Libyan arms link to the IRA - something a republican contributor to the same programme had earlier tried to brush aside as speculation. As something suggested, rather than proven.

And yet that republican will know that the link was as real and as true as soldiers shooting civilians dead on Bloody Sunday; as real and as true as collusion in the Finucane murder.

The IRA may well have been an underground and secret organisation bound by a strict code of silence. And McGuinness and Adams may well argue that they will tell their stories - if we ever have an independent, international truth commission.

But what if we don't? Does the IRA lie continue? And does it continue to the point that, when the truth is eventually told, that people, tired of this play, will just laugh? Is that how much credibility has been undermined?

I have met and interviewed Martin McGuinness many times - including during the 'war' and the years before the peace. And I have spoken to many others about him many times - people in the worlds of security and intelligence.

In those conversations I have heard him described as "a ruthless, dedicated terrorist"; someone who, at the time of the Libyan arms supply, was "central to the escalating [IRA] campaign".

This places him in his war years, way beyond the early-to-mid-1970s, but it only tells part of his story.

He was also central along with Adams in the moves that took the IRA out of conflict and key to those big decisions on ceasefire, decommissioning, the formal ending of the armed campaign and support for policing. Only someone who had a role and a reputation in the fight could have achieved this.

Remember too, that in the pre-ceasefire secret contacts between the British and the IRA leadership, Martin McGuinness was the key figure at the republican end.

Would the government have been interested in communicating with anyone other than someone whom they identified as being of the IRA and capable of delivering that organisation out of war?

The McGuinness story reads across and through many different chapters and as the pages turn out of war and into peace, he remains a central figure.

And he, with others, needs to find the way and the words to tell more of his story; words that take us beyond his very early years in the IRA.

We need to hear something more credible and more believable from him, but not just from him.

Many others need to be at that table of explanation - republicans, loyalists, politicians, security and intelligence personnel, the churches and media. They all have something more to tell.

It needs someone to step out first and it needs a place and a process within which it can be done.

And if that place and process can be found, and if McGuinness can find a way of telling his story, then questions will also be asked of the intelligence system that produced that description of him as "a ruthless, dedicated terrorist".

And what are those questions? They are about the 'dirty war', about agents and handlers, about policy and orders and about the lives that were lost when the puppets and the strings became a tangled mess.

It would take you inside the web of the Finucane murder; inside a killing that is so filthy in terms of collusion that it cannot be put under the bright lights of a public inquiry.

So, this is not just about Martin McGuinness and his story, but about many people and stories in the different corners of this conflict.

The focus on the republican leader at this time is because of his candidacy in the Irish presidential election. We have watched him trip himself up by not being able to answer.

In the absence of a process, republicans need to find a way of changing the script; changing it into something that can be heard and believed.

These are people who have been at the very heart of the big changing moments of the peace process - key to the decisions on ceasefire, decommissioning, ending the armed campaign and support for policing.

In this they have been sure-footed, but faltering, unsteady and unbelievable when it comes to the IRA question.