The day began with Gordon Brown insisting that Northern Ireland would never return to its worst days of violence. It ended with the murder of a police officer by republican terrorists.

The so-called dissidents – those who split from the Provisional IRA when it opted to accept British rule for as long as a majority in Northern Ireland wish it – gave their deadly reply to the Prime Minister only hours after he had returned to No 10 after a lightning visit to the scene of Saturday’s brutal attack on soldiers preparing to depart for service in Afghanistan.

Yesterday Mr Brown said that the peace process was “unshakeable”, but the fatal shooting of the policeman in Craigavon last night will have serious repercussions for Northern Ireland’s future.

Earlier, it was beginning to dawn on the people of Northern Ireland that, for all the political change of the past decade, they could easily be back once more in the midst of the Troubles.

Times Archive, 1979: Five soldiers killed in IRA offensive

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The wife of a senior member of the judiciary kissed her husband goodbye, worrying for the first time in years about his safety. A prison officer checked beneath his car and up and down his street before driving off. Fear hovered everywhere.

On the radio phone-in shows the chatter was brittle. Gerry Kelly, a former IRA bomber and prisoner who shot his way out of the Maze Prison, confirmed in fewer words than his party leader that, yes, finally, Sinn Féin was urging the public to help the police to bring the murderers of British soldiers to justice.

Earlier, Gerry Adams had defended the absence of an expression of regret in his party’s first statement on the killings, released on Sunday long after all other politicians had condemned the murders. “My thoughts are with the families of the two men who were killed and those who were injured,” he told BBC Radio 4. “The Sinn Féin statement was totally and absolutely unprecedented. The history is that the British Army in Ireland is not wanted by republicans, by patriots, by democrats. I stress again that this is not to justify what occurred. Many people have suffered at the hands of the British Army and again I stress that we are in a totally peaceful and democratic phase. We have been very successful in how we have brought the broad republican community to where we are at this moment. I have to be the best judge of how I address this community.”

By now the Prime Minister had arrived at Massereene Barracks, his cortège of black Range Rovers bustling through the gates where, on Saturday evening, two Real IRA members armed with automatic rifles gunned down soldiers and pizza delivery men. During a private visit to the base, Mr Brown met the soldiers who tried to help their comrades. He arrived and left without comment.

Mr Brown finished his conversations at Stormont with Peter Robinson, the Democratic Unionist leader and First Minister, and Martin McGuinness, the Sinn Féin MP and Deputy First Minister, vowing that the political process would not be shaken. Then he returned to London, leaving the stage clear for the local political leaders, until recently bitter enemies.

Mr Robinson, for so long in the shadow of Ian Paisley, made what many regarded as the most statesmanlike speech of his life. Addressing the Stormont Parliament, he said: “It was an act intended to divide us. It was calculated as a means to raise fear and hatred, a plan to cause us to stumble. It was designed to force us to turn back. This is certainly not the time to raise the flag of party politics. It’s a time for every corner of this House and of our community to unite in condemnation and resolve that these people will never win, that we will not be diverted from the course which we have set.

“The responsibility to bring these people to justice does not fall to the Police Service of Northern Ireland alone. It is a duty that is placed on all of us. The continued existence of this institution will be evidence of the failure of the campaign of murder.

“Today we are being tested. This is a moment of truth for us all. We all have a choice to make. On Saturday a challenge was issued. Today, in this House and outside of it, let the answer be loud and clear: we are not turning back.”

Danny Kennedy, deputy leader of the Ulster Unionist Party, said: “These terrorists seem totally incapable of understanding that they are flying in the face of the overwhelming will of the people in Northern Ireland, Great Britain and the Republic of Ireland, who want peace and political stability.”

Yesterday, Mr Paisley praised Father Tony Devlin, the Roman Catholic priest who led prayers for the two dead soldiers. The former First Minister added: “There is grieving, there is despair, but beyond the despair there is being born a spirit of unity that we have never seen before.”

Meanwhile, the police raised hopes that Saturday’s killers would be apprehended. Detective Chief Superintendent Derek Williamson said that the shootings had been recorded on closed-circuit television. The getaway car, which the Real IRA unit failed to destroy, would reveal scientific evidence.

Richard O’Rawe, a former Provisional IRA senior officer in the H-Blocks of Long Kesh, has come a long way from supporting the violence that he once believed would win Irish freedom. Yet he was gloomy about the consequences of the weekend murders. “It could be a new dawn. They’ve already crossed a Rubicon in that they’ve carried out a successful operation – they killed two British soldiers and forced Peter Robinson and Martin McGuinness to cancel their trip to the United States.

“That can only encourage them. And a lot of rubbish has been spoken about the fact that they don’t have an infrastructure or wide support. They don’t need a whole heap of support. All they need is somewhere to hide a few rifles and they could keep this going for years.”

His words sounded prophetic when, a few hours later, police were swamping the Lismore Manor estate in Craigavon, Co Armagh, the scene last night for the first murder of a police officer in the Province since 1998, when Constable Frank O’Reilly, a Roman Catholic, was killed by a loyalist blast bomb in Portadown. Last night’s murdered officer was the first from the PSNI to die at the hands of terrorists. He was shot from derelict land as he and a colleague sat in their patrol car.

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