Less than a year ago, the sight of Ian Paisley and Martin McGuinness in the same photo frame, smiling as they pursue with obvious enthusiasm and apparent goodwill, the task of establishing a power-sharing administration in the North, would have been inconceivable.
That it is happening daily is enough to upset those who would seek to prevent political development - either the doubters on the fringes of the DUP, who deride the pair as the 'chuckle brothers', dissident republicans, with eyes firmly fixed on the rear-view mirror; or some traditional unionists, who resent the DUP having stolen their clothes.
Equally surprising is that both Sinn Fein and the Orange Order should be under threat from a common enemy, the Real IRA.
Arson attacks on isolated Orange halls, often the only community facility in their areas, have increased in recent months. In the main, this is an exercise in crude sectarianism in the guise of patriotic struggle. It may be a device to keep idle hands employed; but if there is a deeper, more strategic purpose it is to destabilise society by driving a wedge between communities, rekindling old animosities and forcing loyalists to react.
The more sinister, and murderous working out of this strategy is seen in the shooting of two off-duty PSNI officers, one a Catholic leaving his child to school. This is an old republican ploy to force police, and particularly Catholic officers to resign or to break their links with their own community.
This strikes at the heart of the Patten reforms of policing. It is an indicator of the success in implementing these proposals that the proportion of Catholic police officers is now three times what it was, and that nearly half the applicants to join come from a nationalist background.
If a campaign of murder were to deter recruits from republican areas, or to force serving officers to move away from family and friends, then that would indeed be damaging.
It is significant that Sinn Fein members targeted are local councillors who are members of local Policing Partnerships - another Patten innovation designed to make policing responsive, and responsible to the community served.
It is ironic that for years the same sort of treatment was dished out to SDLP members of Policing Boards by the whole spectrum of republican activists.
Not to be outdone, dissident members of the UDA from the highly factional south-east Antrim area are emerging to issue threats - this time to SDLP politicians.
A more serious external threat to the Executive lies in the attempts being made to establish a link between Sinn Fein and the murder of Paul Quinn just across the border from south Armagh.
If it were to be found that this was officially sanctioned and carried out through IRA command structures, in contradiction of all assurances that have been given, and all the condemnations that have been intoned, this would test, almost to destruction, the ability of the DUP to hold their followers together in support of co-operation in government with Sinn Fein. If, however, it is proven to have been carried out without IRA involvement, even if some of those involved had a previous association; that it was unsanctioned and repudiated in a way which delivered the culprits to justice, the DUP could probably weather the storm.
More prosaically, however, the chief threats to the Executive come from within. They are those facing all governments which fail to deliver.
The widespread public goodwill which the Executive collectively now enjoys will quickly dissipate as expectations fail to be met. The feelgood slogans about togetherness can only carry a government so far.
Few expect miracles in a short time, but unless there is evidence that the Executive as a whole can face up to, and make, tough decisions in pressing matters of social and economic policy, public patience will run out.
They badly need one big decision on an issue where there are real divergences of policy, if only to show the world that they can do it.
Before the election, the parties were deeply divided on the question of selection for secondary schools. Children last week took what is declared to be the last such qualifying exam. As yet, nobody knows what is going to replace it.
Teachers, parents and pupils face into the new school year in the dark.
Meanwhile, the Bank of England is being gloomy about growth in the British economy, to which the North is umbilically linked, and there are looming cuts in public expenditure as the Treasury sharpens its axe for the regions.
These are the real challenges for the Executive. They are the challenges faced by any government in a democratic society. The sooner they face up to them, the better.