Dissidents must be thwarted at all costs
The upgrading of the terrorist threat in Britain from dissident republicans is a very worrying development. It suggests that the renegade groups are growing in sophistication and have more widespread support than is commonly imagined.
Launching an attack on targets in England, Scotland or Wales requires a lot of detailed planning and a network of supporters on both sides of the Irish Sea.
MI5 believes that there is a strong possibility of dissidents attacking targets in Britain. This is not an assumption made lightly, and the fact that Home Secretary Theresa May has acted swiftly on it reflects the gravity of the situation.
This is a jolt to assumptions often made in Northern Ireland, where the dissidents are regarded chiefly as disaffected former IRA members who rejected the peace process and have gained some support from young people in certain pockets of the province.
While no one underestimates their potential to take lives, as the deaths of two prison officers, two police officers and two Army sappers during the past decade testify, many other murderous attacks were foiled either by good luck or good intelligence.
But the dissidents are also turning their guns on civilians, again with fatal results. Witness the deaths of Michael McGibbon in Ardoyne and Dan Murray in west Belfast in recent weeks.
There has also been an upsurge in so-called punishment shootings, and a priest says he knows of 25 people who are under death threat from dissidents.
He makes the telling point that the dissidents are men who hide in the shadows, emerging only to carry out their foul deeds but unable to give any justification for their campaign of terror. They are replaying the past at a time when the vast majority of people want to enjoy the present and create a better future.
Given that they may now be considering widening their campaign, it is imperative that police forces and intelligence agencies throughout the UK and the Republic of Ireland co-operate as closely as possible to ensure that maximum pressure is kept on the terror groups and that their evil intentions are thwarted at every turn.
There can never be an acceptable level of violence, and now that the British public has been alerted to the dissident threat, perhaps there'll be an even stronger response from the intelligence and security services than currently exists.