David McKittrick: There's life after Paisley for Northern Ireland Paisley

A mighty oak has crashed to the forest floor in Northern Ireland with the ending of the truly astounding political career of Ian Paisley, greatest of the demagogues, colossus of the troubles.

Most of that career was not a pretty sight, featuring as it did all those torrents of bile and bigotry: the charge against him will be that he played on fears and at almost every turn sought to make bad times worse.

Northern Ireland experienced 40 full years of that before witnessing the dramatic coda which, as though by the application of fairy dust, saw the old Raging Bull suddenly become the new symbol of benign partnership.

It has been less than a year since Paisley stood alongside Sinn Fein's Martin McGuinness to speak of "wonderful healing", switching effortlessly from the old fiery bombast to the new sweetness and light. The U-turn was so dramatic that even today many still shake their heads in wonder at the sight of what McGuinness describes as a "cordial, civilised, positive working relationship". The Paisley roar has turned into laughter.

It was the four decades of belligerence that enabled Paisley to deliver eventual harmony. As nationalist commentator Brian Feeney wrote yesterday: "He alone could have sealed the deal with Sinn Fein, because his 45-year divisive career of ranting, stunts, threats, protests, walk-outs and phantom armies made it impossible for any other unionist to do so."

And now, while the speculation as to why Paisley did it is still going on, a new question has arisen: is his resignation an entirely voluntary act, or was an element of propulsion involved?

The financial and business involvements of his son, Ian Junior, have produced an endless stream of embarrassing headlines. Junior had to resign his ministry lately, his dad's over-indulgence of him helping to unsettle the party ranks.

Then again, unsurprisingly for a man of almost 82, much of the old energy has gone. He can still flare up from time to time, but his legendary stamina is flagging. He is not a natural administrator; power came late to him; and some of his authority is very obviously dwindling.

A recent council by-election produced an unexpected loss for the party. And with the loss of his son came the question of when his own departure might happen. As Tony Blair and other leaders have found, once the speculation starts, it never stops.

So it was that Paisley saw the writing on the wall. He would have preferred to stay on a while longer, but in May he will reach his first anniversary in power, and he will host an economic conference. The two events combine to make it a convenient moment to call it a day.

He made much of the economic conference in his farewell remarks: in truth it's not that big a deal, but it is helping him depart with dignity.

It is not yet clear exactly what spurred him to go at this point, but the major factor is that he went a chuckle too far. While the Protestant population was amazed at his compact with Sinn Fein, most unionists accepted the time had come to co-operate with nationalists and republicans.

But the Paisley-McGuinness bonhomie was an extra-difficult pill to swallow, many balking at the notion of being so matey with Sinn Fein. Paisley's party has taken this on board, so it is a certainty that its next leader will assume a more distant approach.

This will take no great effort on the part of Paisley's deputy Peter Robinson, who is highly likely to get the job, since he is a reserved man not known as a back-slapper. But he is efficient, and clever, and already works well with Martin McGuinness.

The departure of such a prodigious figure as Paisley, the ogre who morphed into a friendly giant, will inevitably generate anxieties for all those who support the peace process. Time was, before his conversion, there would have been widespread celebrations at his demise.

But now the manner of his going offers good prospects for a smooth transition. One bookie is giving odds of 1-14 on that Robinson will succeed him, first as party leader and then as First Minister.

Like Paisley, Robinson has been around for decades and is skilled in internal party management. There are various loose ends around in the peace process: for example the IRA is inactive, but its ruling army council is still in existence.

The powersharing administration runs areas such as health and agriculture, but there are disagreements about when policing and justice issues should be devolved to Belfast. There are difficulties over the Irish language, education reform and what to do with the old Maze prison.

Once in power, Robinson may aim for a round of negotiations which would sort out most or all of these and simultaneously stamp his personal authority on both the party and the government.

Sinn Fein for its part will press its views on the individual issues, but it will do everything it can to ensure a smooth transition. Many in republican ranks were less than ecstatic about being part of a government headed by Paisley, but it was all part of getting into power.

Similarly, Robinson is acceptable as the next First Minister. Like Paisley he had an extremist past and clashed with republicans on innumerable occasions – Gerry Adams once called him a coward – but he has been on the same odyssey as Paisley and is a committed powersharer.

Adams and McGuinness were among the earliest advocates of the peace process – even as the IRA continued killing people – while Ian Paisley and Peter Robinson were late converts.

Yet what affected all of them was not fairy dust but political reality. Both realised that victory was not possible, that they would have to settle for compromise.

In the end the intrinsic logic of the peace process prevailed, because of its obvious benefits: the war stopped and in terms of voting strength both Sinn Fein and Paisley prospered.

For Paisley the additional personal advantage was to give him his year at the very top of the political tree, accepting the plaudits of the world as the towering figure who finally helped bring peace.

Now the logic, and the likelihood, is that the system he helped establish will survive his departure: certainly his party, Sinn Fein, and London and Dublin want it to. The era of Paisley is at an end, but the era of the peace process looks like it is here to stay.

d.mckittrick@independent.co.uk