Vladimir Putin will today convene an emergency meeting of his top military and security chiefs to discuss the fall-out from the downing of the Malaysian Airways plane by pro-Russian rebels in eastern Ukraine.

Judging by his most recent public statements on the matter, he is in a foul mood, and may well haul some of those attending over the coals. For it is they, the men who have secretly supported, trained and armed the separatists, who have landed Mr Putin with one of the biggest challenges of his presidency.

There is no doubt he supports the rights of Russian speakers in Ukraine (and in other countries neighbouring Russia). But it is less certain that he supports the undisciplined, hot-headed gangsters who have been seen obstructing the MH17 recovery operation. He has never given wholehearted support to these self-proclaimed leaders of the so-called "Donetsk People's Republic", nor to their wish to separate from Ukraine. On the contrary, he called on them to postpone their independence referendum in May and, when they went ahead anyway, he refused to endorse the results.

There is every sign he is appalled by the fact the rebels, acting in the name of a cause he supports and armed by his own security services, have turned out to be so incompetent as to bring down a civilian airliner, apparently mistaking it for a Ukrainian transport plane. If, as seems likely, an international inquiry proves they fired the deadly missile, the tracks will lead back to the Kremlin, putting Mr Putin in a hugely embarrassing position.

He cannot possibly defend the rebels' action and will doubtless try to distance himself from them. His covert forces have been busy eliminating the traces, removing the Buk missile system back into Russia and out of reach of investigators. Covering up the traces of a crime is despicable. But if Mr Putin is forced to disown the rebels, this might at least afford an opportunity for the West to re-engage the Russian leader in the process of bringing peace to Ukraine. David Cameron, while threatening tougher sanctions, recognised at the weekend there must be protections for Russian-speaking minorities in Ukraine.

This might be the key. If Mr Putin is looking for a way to save face, the West might be able to persuade him to kick the separatists (who, he has discovered, are a liability) out of the Donetsk region, and to help bring it back under Kiev's control, on the promise there will be immediate and meaningful negotiations on a federal system in Ukraine that would guarantee Russian rights.

Ukraine's leaders would doubtless dismiss such a suggestion, for two reasons. It effectively lets Mr Putin off the hook for a crime in which Russia seems to be complicit. And it amounts to giving Russia a say in how Ukraine is run. But the alternative is surely worse: a continuation of the civil war, and the constant danger of a repeat of the catastrophe of MH17.

The Russians of eastern Ukraine have rights. They may be fighting for them in utterly the wrong way but conceding a federal constitution that preserves Ukraine's territorial integrity seems a small price to pay if it brings peace.