Now we are in trouble. The problems that lie in front of us following the murders in Massereene should be clear enough but perhaps aren't.
If this is the beginning of a reenergised campaign by republican militants, then there are basic lessons from past experience that need to be borne in mind.
This can bring down the Assembly.
It is good to hear the first ministers asserting emphatically that it must not be allowed to, but they know their history better than most. No power sharing government has ever functioned here against the backdrop of an ongoing republican campaign. The SDLP calculated that it could not share power with Unionists at a time when it would have been answerable for security measures against the IRA and its support base in the Catholic community.
Sinn Fein may be in a better position for a time, but another lesson is that these things get worse before they get better.
There is no precedent of a paramilitary organisation in Northern Ireland being put out of business by the state through policing and security measures.
Suddenly people are talking as if this is a feasible option. Well, it has never happened before.
What tends to happen is that the measures taken by the state are turned to the advantage of the paramilitaries. Strong arm measures are condemned as oppression and harassment. How much strong action is Sinn Fein likely to sanction, when Alex Maskey, a security spokesman and a member of the Policing Board was ranting at the recent Ard Fheis about the injustice of stop and search measures, directed against dissident republicans?
A crucial demand of Sinn Fein, and a condition of their participation in the Executive, is early devolution of policing and justice.
The murders complicate this in several ways, not least perhaps in that Sinn Fein might want powers over policing in the hopes of curtailing aggressive and covert action against the dissidents, or that Unionists, suspecting as much, will now feel more inclined to push devolution further back.
Another lesson is that while most of us are appalled by the murders, some will be impressed. The dissidents will be seen in some quarters as having upped their game and made themselves credible militants.
This can attract new members.
The man behind the eight ball today is Martin McGuinness. Those who carried out these murders knew that he was their real target. Their job is to make his job impossible.
McGuinness, like many others, was probably waiting for the first success of the dissidents to be the murder of a Catholic police officer. That would have been more manageable than this, for the whole Catholic community would have swung round unambiguously. This is much more difficult for him. This touches his republican funny bone.
McGuinness has a limited amount of leeway, so long as this doesn't get worse.
He is already taking care to explain — in his convoluted phrasing — that he has no choice but to call for people to help the police, and that doesn't sound like enthusiasm; it sounds like conceding that normal civil responsibility is an onerous political duty.
A key question is whether the dissidents are within reach of significant goals, and are brought closer to them by these murders. We have to sensibly conclude that they are and not try to wish that thought away or to smother clear headed debate with moralising.
Those of us who remember the Troubles will recognise the tone of unction in the statements of condemnation of the Massereene murders. They will be wincing at the prospect of well intentioned people making things worse. Secretary of State Shaun Woodward's appraisal of the soldiers killed as fine young men who wanted to save lives serving in Afghanistan may have been perfectly true. But, if not, it makes no difference to the ghastliness of their murder and the scale of the political problems created by this ambush.
It does, however, have the potential to rattle a republican culture which doesn't want to see endorsement of the army's role in Afghanistan as part of the moral package it has bought into through the peace process.
In fact, to many it will smack of lines being drawn between those who revere that role and those who want to murder soldiers. It would be better to focus on the politics of Northern Ireland and leave Afghanistan out of it.
Woodward will achieve nothing by sounding off plummily as if he thinks he only needs to be heard in the Home Counties.
Does Woodward know, for instance, the resonance of the word ‘criminal' in republican culture? Yet he uses the word so often you would think he was deliberately trying to echo Margaret Thatcher in his taunting of the dissidents.
These are hard times and a lot of people are going to have to try and think a little more like their old enemies if we are to get through them.