Welcome back to Northern Ireland, Dr Richard Haass. You know the ropes and you have already helped us through the impasse on IRA decommissioning.
But flags, parading and the past could prove tougher. They have been avoided until now precisely because every one of them has the capacity to split the Executive down the middle – even, in the worst case, to destroy it.
It is quite genuine and their speeches at the Assembly were impressive.
The fact remains, though, that they were unable to agree a common statement, or a common response, to a Parades Commission determination on a section of a single Orange march stretching for 30 yards.
The day before the determination, the five Executive party leaders issued a statement saying: "Whatever any of the parties may believe about the wisdom of any Parades Commission determinations, it is the lawful authority dealing with these matters and its decisions must be observed.
"We appeal to community leaders and, indeed, others, such as parents, to seek a peaceful parading season to avoid an impact on our citizens, through damaged community relations, or the life-restricting consequences of criminal records."
If Peter and Martin had appeared together to say something like this after the determination, it might have calmed things, but it wasn't politically possible.
Instead, DUP politicians took their cue from the Orange Order by expressing sympathy for protests and lambasting the decision.
Sinn Fein also had to play to its own constituency for a few days.
No unified approach was possible; even at the Assembly, they backed different motions, each of which got roughly the same number of votes.
It would have been worse if they didn't have the Parades Commission as a whipping boy. Think what would have happened if, for instance, the decision had been taken by a body responsible to the Office of the First and deputy First Ministers (OFMDFM).
Could they have stood over it? Or would someone have tried to veto it and walked out if the veto wasn't effective?
They were lucky they had the Northern Ireland Office and the commission to act as crash-test dummies. An OFMDFM-appointed body could organise mediation between parading organisations and local stakeholders – that could work, with the example of Londonderry to guide it.
But we still need an independent body to adjudicate where agreement isn't possible.
The body taking those tough decisions shouldn't be answerable to local politicians and it should have a more judicial air to it than the present Parades Commission, whose determinations often seem arbitrary.
Determinations should build up as a body of case law, like the findings of an industrial tribunal, to ensure consistency and build confidence.
Decisions must be quick and clear – there is little breathing space before a disputed parade.
So, if a determination is successfully challenged, the result may be too late to affect events on the day, but it could set binding ground rules for future decisions.
That might work. But local politicians need shielding from tough decisions.