With every wicked, taunting act of violence, the IRA brings us back a step along the road towards Loughinisland, Greysteel, Frizell's fish shop and all the other placenames of atrocity and pain that dot the map of these islands. The bomb defused by the British Army at New Year contained 1,000lb of explosive, sufficient to cause many deaths and injuries had it gone off in a populated area or without warning.
Some commentators suggest that we are witnessing a form of posturing, demonstrating a capacity to strike without inflicting serious injury. If so, it is a highly dangerous process which cannot be sustained indefinitely. Sooner or later the IRA will kill and maim on a scale and in circumstances which will snap the last vestiges of Loyalist restraint.
It is inevitable - unless a new ceasefire is instituted. And in the present political realities such a ceasefire represents the only possible means of forward movement for anybody. Mr John Hume spoke, on RTE radio yesterday, in the most anguished terms, of the failure of the British government to respond to the talks proposals which he had advanced in October.
The governance of the United Kingdom is effectively in abeyance. Mr Major's administration is limping and dragging itself towards election day, beset by political failure, sleaze and a crisis of public confidence. Any hope that the Prime Minister might seek to take the high moral ground by striking out with a new initiative on Ireland has been buried. There can be no progress on anything until a newly mandated administration sits at Westminster.
And does this not add to the fatuity of violence? Which of the IRA's purposes can be served by waging war on a government which is functionally dead? What pressure or persuasion can be brought to bear upon a Prime Minister and Cabinet who are taking the last tottering steps towards their reckoning with a disillusioned electorate? Is there anybody in the IRA's senior echelons who believes that a millimetre of flexibility can be bought at this time by killing or maiming?
Within a couple of months at longest, the British general election campaign will be under way. If the Republican movement is to take the political path, it will have to do so very rapidly for there is no doubt that the size of Sinn Fein's support will depend on whether it can demonstrate an unequivocal support for purely peaceful methods. There are tempting prizes within the political process. In contrast, where do the Provisionals strategists believe there is anything to be gained in murdering policemen or their own Loyalist counterparts?
On RTE radio yesterday Mr Hume made some observations which are worth underlining about the relationship between Sinn Fein and the IRA. He did not doubt, he said, that one represented the political voice and one the armed wing of the same movement and that they support each other's strategies. Yet, Sinn Fein spokesmen comport themselves as if they were as remote from the IRA as the Society of St Vincent de Paul.
They cannot have it both ways. If the IRA continues to throw tinder into the powder shed there will be a conflagration. And Messrs Adams and McGuinness will not persuade many that they stand for something different. If the voters are obliged to step to the polling booths through streets once again bloodstained and blasted, can Sinn Fein expect any better than continuing pariah status? And the SDLP must have nothing to do with their proposed joint electoral strategy reported this morning.