LONDON, England (CNN) — When Northern Ireland’s police chief, Hugh Orde, warned a week ago of a heightened threat from dissident Republicans he did not mince his words.

“We are very clear,” he said, “they are determined to kill police officers going about their normal duty of keeping people safe.”
It now appears those fears have been confirmed.

The fatal shooting of a police officer in the town of Craigavon, not far from the capital, Belfast, comes just 48 hours after gunmen shot dead two British servicemen at a barracks in the province.

The Republican splinter group, the Real IRA, claimed responsibility for that attack. And no one in Northern Ireland will be surprised if they claim responsibility for this latest one as well.

Membership of the Real IRA, a rump of Republican activists who refused to go along with the main Provisional IRA, and its political partner Sinn Fein, after the 1998 Good Friday Agreement that set Northern Ireland on the road to peace, is put in the low hundreds. But as so often with violent extremists, they have a power to shape events out of all proportion to their size. Or so at least they will wish to believe.

These targets are not randomly chosen. By targeting the police, and particularly the British army, they are hitting Republican weak spots. Sinn Fein, fully signed up to the peace process and a key partner in the power-sharing government, makes no bones about the fact it wants to see all British troops out of Northern Ireland. Like it or not, Gerry Adams finds himself in a difficult position being forced to condemn an attack on the British army. Calling on Republicans to grass on those who carried it out is another, even more problematic, step to take.

What the Real IRA wants to see happen is an over-reaction from Unionists and a move by the British government to put soldiers back on the streets. Political Republicans are highly sensitive to these possibilities. Hence the sharp criticism from Sinn Fein before these attacks to news that the intelligence arm of British special forces had been called into the province to meet the rising dissident threat.

The response to the attack over the weekend suggested the consensus that governs Northern Ireland — that all sides keep dancing together in the name of devolved government and the peace process — was holding. If that changes then the dissidents will hope their shocking show of strength can win new support.

What’s worrying is where that support might come from. Paul Dixon of Kingston University points out the apparent anomaly that support for those political parties that have most readily embraced the peace process has tended to come not from the young — those, on the face of it, with the most to gain from peace — but from the older generations, those who’ve grown weary of decades of violence. The fear is that the readiness of many younger voters to support those parties who’ve taken a tougher line on the peace process might translate into a new generation ready to abandon peace altogether.

One Northern Ireland politician said after the latest killing that the province is “staring into the abyss.” It’s a frightening thought that the foundations of peace in Northern Ireland might really be so shallow.

But amid the pessimism, it’s worth recalling that previous attacks in the province have sometimes succeeded in actually embedding the peace process further, through a shared revulsion to the violence from across the communities. The challenge to Northern Ireland’s politicians, its police force, and the British government, is that they collectively hold their nerve and bring their people with them.