The death of Adrian Ismay has been met with almost universal horror across Northern Ireland, alongside condemnation of his killers.
It is a sign of how far the Province has come since the Troubles that the terrorists seem so isolated.
But they are still able to inflict serious harm on society.
There have been many foiled operations against dissidents, and police and others have consistently warned that they have the capacity to kill, and that people will die. Mr Ismay was a long-standing prison officer. He was attacked in east Belfast, which is no safe place for republicans.
The targeting of prison officers is a deliberate bid to instil terror in specific categories of people, including Catholic PSNI officers.
The threat against prison officers is a sickening extension of the endless agitating by dissident thugs at Maghaberry, who issue one demand after another.
It is important that no concessions are given to these violent and dangerous terrorists. Any politicians or human rights advocates who are foolish enough to endorse the dissident demands should be ignored.
In fact, we need tougher jail terms for violent dissidents.
It is hard to apprehend and convict terrorists, because they are so skilled at covering their tracks. The murders of Sappers Mark Quinsey and Patrick Azimkar, Stephen Carroll in 2009, Ronan Kerr in 2011 and David Black in 2012 have only resulted in two murder convictions (for the Carroll murder).
One of those two, John Paul Wootton, will be free a mere 10 years from now, after calculatedly ending someone else’s life.
The intelligence services who track such killers need generous resources and unequivocal support, as do the police who have to try to thwart them. Sentencing guidelines should be increased.
Dissidents cannot be wooed through kindness or concessions. For the sake of their targets, and of the whole community, we must get tougher with them.