Gerry Adams has called for a meeting with the group which left an explosive device in the driveway of his home in west Belfast on Friday evening, so that they might explain their actions. "That's my direct appeal to them," he declared at a press conference yesterday. "Give us the rationale for this action."

It's no great mystery. The explosions at the homes of Adams, inset, and Maze escapee Bobby Storey are believed to be the work of dissident republicans. Groups such as the New IRA, Oglaigh na hEireann, Continuity IRA, and all the rest, remain in existence because they wish to end the British 'occupation' of Northern Ireland, and believe that any means necessary is justified in doing so, including targeting those they regard as traitors to the Irish cause for following the path of constitutional politics.

In other words, dissidents believe exactly the same ideology which republican leaders such as Adams advocated most of their political lives.

There are fewer of them around these days, but Irish freedom has never been a numbers game to its deluded champions. It's always been about the indivisible right to self-determination. Just because a preponderance of former Provos no longer hold the view that violence will achieve their ends doesn't mean that those who do still believe in terrorism as a legitimate tool of resistance must submit to majority opinion, any more than the IRA of Adams's generation did when it was in a minority.

The attacks on Adams's and Storey's homes should be condemned by all strands of political opinion. Indeed, they already have been. Democratic politicians don't need to be prompted to express revulsion at terrorist bombings.

The explosions were small in comparison to many of those which have repeatedly brought tragedy to Northern Ireland down the decades, but the damage to the car parked outside Adams's house shows that these fanatics weren't simply sending a message. The "large industrial, firework-type devices" recovered from the scene are capable of causing serious harm. But it would be equally irresponsible not to point out that the ambivalence which Sinn Fein continues to display toward political violence is part of the problem.

Asked by a German newspaper earlier this year whether violence was a "legitimate means with which to reach one's aims", Adams replied that it was "in given circumstances". His opinion is that the circumstances in the North during the IRA's long war did justify violence, but that's nothing more than an opinion. Once terrorism becomes a subjective matter of judgment, there is nothing to stop dissident republicans from concluding that the circumstances still exist to justify bombs.

Mary Lou McDonald cannot escape these contradictions either. Commenting on sectarian violence which has scarred Derry nightly since last weekend, Sinn Fein's new leader slammed the "warped, negative, regressive and dangerous" agenda of dissident republicans who are believed to be orchestrating the trouble, whilst ignoring the fact that it's exactly the same agenda which was pursued by the Provisional IRA, from whose atrocities she still refuses to distance herself and her party.

Earlier this year, McDonald attended a memorial to an IRA volunteer who died when the device he was planting exploded prematurely. If he is a hero, why should 'dissies' not believe that they are too?

Until Sinn Fein is prepared to honestly acknowledge that the dreadful 'war' it supported for so long was misguided, it will always have zero credibility when condemning violence.

In his tweet on Friday night, thanking those who rushed to the scene to help after the explosion, Adams did not even mention the PSNI, who that week had also been coming under machine gun fire from dissidents in Derry.

And still Sinn Fein scratches its head and pretends to be confounded that young people in nationalist areas might be falling under the seductive influence of sinister elements? That's no great mystery either. Ambivalence always leaves open the door to further violence.

Sunday Independent