Ukraine crisis: Who benefits from the Minsk peace deal
Who does this new Ukraine deal seem to favour most? The rebels and Russia? Or Ukraine? In theory, the most immediate tactical advantage seems to go to the rebels, and therefore Russia too.
Though the rebels must pull back from the ceasefire line as defined last September, the Ukrainian forces have to pull back from the line of control as it exists today.
In other words, the Ukrainian army is being asked to retreat from ground it was fighting for during last month's rebel advance.
President Petro Poroshenko has admitted there are other points where his demands were not fully met.
He asked for an immediate ceasefire. In fact it will not take effect for two days.
He wanted a commitment for all foreign troops to be withdrawn from the region. It is in the text, yet will Russian President Vladimir Putin feel bound by this, given he denies Russian forces or weaponry are there at all?
And though Ukraine is supposed to take back control over its border with Russia - another key demand, to prevent Russian weaponry from flowing across again - this will not happen until the end of the year and only if certain conditions fall into place.
First, a new Ukrainian constitution must come into force which will grant the eastern rebel regions wide powers to form their own police force, appoint their own judges, and conduct cross-border trade with Russia.
Yet though President Putin's grin as he presented highlights of the plan to the press suggests he thinks he is the winner here, maybe in the longer term - if this plan gets that far - it could work to Ukraine's strategic advantage.
Underpinning the document is an assumption of Ukrainian sovereignty - that in the end, all rebel-held territories and borders should come back under Kiev's ultimate control.
The rebels' self-proclaimed Donetsk and Luhansk republics are never mentioned. Nor is there any reference to earlier calls for rebel self-government inside a looser federal state - an idea Russia toyed with as a way to weaken Kiev's hold on the east of the country.
On the contrary, Russia is now pushing for re-integration of the rebel regions into Ukraine through the restoration of economic links which Kiev cut off in the autumn: the reopening of banks and the payment of pensions and resumption of other services, so that residents of rebel areas would no longer be forced back onto Russian humanitarian aid.
Possibly given Russia's current economic problems, President Putin calculated he did not want to be saddled long term with the burden of propping up the Donbas region.
Possibly Mr Putin also reckons that he needs these Russian-speaking areas to stay firmly inside a Ukrainian unitary state, to maximise his leverage on Ukrainian politics.
But if Kiev does take back economic responsibility for these regions, it also has a chance for the central government to recast itself.
What better way to make locals feel more receptive to the idea of being Ukrainian than for them to see Kiev as a benevolent force which takes care of welfare (and here the new IMF loans just announced may be useful), instead of a ruthless military force which shells their homes in a pointless war?
Much would depend on new elections for the area, supposed to be carried out under Ukrainian law, and whether they brought in new political leaders, no longer loyal to Moscow.
But all that is still hypothetical. The more pressing question is: can this deal get off the ground at all? After all, it looks suspiciously like the failed Minsk deal of last September. So what is there to stop it failing again?
Perhaps one slim hope is the changed context. Since September the military conflict has worsened, with many fearing it could spiral out of control. In political and economic terms, the rebel-held areas have become more detached from the rest of Ukraine.
And internationally, the rift between Russia and the West has widened alarmingly, to the point where the US president has begun to think about whether to send weapons to Ukraine.
Sense of urgency
All this helped inject a sense of urgency and desperation into this week's diplomacy. It was what prompted the French and German leaders to offer themselves as godparents and effective guarantors of the process.
It was what persuaded both President Putin and President Poroshenko to travel to Minsk. It was what drove all four leaders to stay up all night arguing, as they thrashed out enough common ground to declare a ceasefire.
As several participants have said, this looked like a last chance for a negotiated peace. To walk away would be to look into the abyss.
There are plenty of pitfalls and weaknesses about this tentative deal. It would not take much for the whole fragile house of cards to come tumbling down. But perhaps fear of new failure could help give this half-baked agreement half a chance.