Did Mr David Trimble conclude the agreement on Good Friday? Does he understand what it entails? Does he intend to deliver? And will the Assembly election results enable him to do so?
Enthusiasts for Northern Ireland's "new" politics have little time for such reflections. With admirable, and clearly necessary, optimism they can see all things coming together for good: including, even, the seeming contradictions in Mr Trimble's position as he battles for electoral advantage over the DUP.
Last week Mr Martin McGuinness told The Irish Times why the new politics wouldn't enable Sinn Fein to recommend that their supporters give later preferences to pro-agreement Ulster Unionists. Mr Trimble, he charged, had "said Yes once" to the agreement. But nationalists remained highly sceptical.
Would he say Yes to dialogue with Sinn Fein in the Assembly; and to working with them in the Executive, on the North South Council and in implementing the equality and reform agenda? Party politicking? Predictable knockabout stuff to be swiftly forgotten as the heat of the hustings subsides? Well, maybe. But Mr McGuinness is a serious player. And it is significant surely that the nationalist scepticism to which he referred found new voice this week from the deputy leader of the SDLP, Mr Seamus Mallon.
Nationalist restraint has been a remarkable feature of the post-Easter period as, first in the referendum campaign, and now again in the Assembly contest, the primary focus remains on the battle for the soul of unionism. They "bit their lips", as Mr Mallon put it in his Irish Times interview yesterday while Mr Tony Blair, on at least three occasions, came here to bolster Mr Trimble's position, coming close to rewriting the agreement in the process.
Mr Seamus Mallon's decision to break silence and speak out now, with a week still to go to polling, must be seen as a measure of the rising nationalist anxiety about Mr Trimble's current direction, and the extent to which the British government is prepared to go in order to sustain him.
Mr Mallon, like British and Irish ministers, not to mention anti-agreement unionists, was astounded by Mr Trimble's last-gasp decision to vote against the Bill providing for prisoner releases, and thus affecting one of the key elements of the Belfast Agreement, in the Commons last week.
The Ulster Unionist leader yesterday said it would be "churlish" not to acknowledge "significant concessions" by the government and indicated he would not be repeating his opposition to the Bill in last night's vote on Third Reading.
However, he did not choose to finesse his about-turn by attending the Commons debate, so once again vacating the parliamentary stage, leaving his designated spokesman Mr Jeffrey Donaldson and other dissident colleagues to vote with Dr Paisley, Mr McCartney and the Conservatives against the Bill.
It seems decidedly careless of Mr Trimble to have failed to keep the Conservative front bench on-side. His own `parliamentary party' is a mess, as witnessed again last night. Torn apart by the agreement, even the pretence of cohesion is now beyond the UUP MPs.
But in addition to the recurring question of Mr Trimble's command of his troops and his ability to deliver them, the nagging nationalist worry is over his failure to prepare them for what lies immediately ahead.
As Mr Seamus Mallon made clear yesterday, the core of that concern lies in Mr Trimble's interpretation of the agreement, and the transitional arrangements to come into play before the transfer of powers to the Assembly.
As far as Mr Mallon (and Sinn Fein, and the Irish Government) are concerned, the "shadow" Executive should be in place by the middle of July. Mr Trimble says not until close to Christmas, "if then". And the UUP leader's "if" carries the clear implication that Sinn Fein's entry into government (assuming the appropriate mandate) is not yet guaranteed.
Pressed on this point, Mr Reg Empey, one of Mr Trimble's key negotiators, and a putative member of the Executive, says there are indeed no guarantees. Sinn Fein, he asserts, "haven't convinced me they are wedded to peace, and until they do I won't treat them as such."
He says unless the illegal weapons are "dealt with" they become a threat in turn to the organisation which holds them. And he insists: "These guys have got to pay a price." Mr Empey denies that the Ulster Unionists are, in effect, seeking to continue the negotiation. Rather, he says playfully, they are simply moving "into another phase in the struggle".
Nationalists don't quite know whether these are the words of politicians seeking cover under the weight of electoral challenge, or if they reflect the reality of UUP thinking about what comes next.
What Mr Seamus Mallon, Mr Martin McGuinness and others are clear about is that the Ulster Unionist leadership's projections do not accord with the reality of the agreement, or the nationalist expectations which flow naturally from it. The anxiety is how unionist members will respond - in what may be a tightly drawn Assembly - when the reality intrudes, as they predict it soon will.
Turning to next Thursday, the specific question is (Mr Trimble having already seemingly reduced his room for manoeuvre)how much further his capacity might be reduced by the electorate.
The UUP won't predict the likely number of unionist seats, not least because they don't know how many of the referendum's "new" voters will stay the course. But they and the DUP are clearly working on the assumption of around 60 of the 108 total.
Dr Paisley says the DUP/UKUP bloc can claim 30. So even by their own forecast, they would not have enough to thwart Mr Trimble, courtesy of the Assembly's complex rules for sufficient consensus.
Short of the magic 60 per cent of the unionist total, their hopes would then rest on declared anti-agreement Ulster Unionists, and those Mr Peter Robinson describes as "the trojans", UUP doubters ready to ditch Mr Trimble at the first sign of trouble.
Glengall Street sources offer varying assessments of the likely durability of some of the antis, once ensconced in well-paid jobs at Stormont. But even allowing for question marks over two or three, the No camp claim six UUP candidates firmly as their own: Mr Roy Beggs jnr (East Antrim), Mr John Hunter (South Antrim), Mr Jim Rodgers (East Belfast), Mr Jim Clarke (South Belfast), Mr John Junkin (Mid Ulster) and Mr Peter Weir (North Down).
All six are considered to stand a good chance of election. And their potentially pivotal role is revealed by one private UUP forecast which would give the UUP (plus the PUP) a total of 35 seats, to 24 for the DUP and UKUP.
In that scenario just six defections on a crunch issue could quickly convert the unionist arithmetic, handing Dr Paisley and Mr McCartney the crucial psychological advantage of heading the larger unionist grouping.
One of Mr Trimble's most implacable opponents predicts that the "crunch" will come if the UUP leader decides to enter even the "shadow" Executive without a prior start to decommissioning by the IRA. He also predicts Mr Trimble will do so because the agreement (and Mr Blair) require it, and he cites the leadership's refusal to permit Mr Donaldson's candidacy for the Assembly as evidence of its intent.
Mr Donaldson meanwhile is waiting in the wings, watching for the convulsions his supporters say have yet to afflict unionism and which will, in due course, lead to a realignment around him, Mr Robinson and Mr McCartney.
On Good Friday it was possible, as one broadcaster put it, to believe everything had changed, "and utterly". We didn't guess the half of it.