Russia’s military intervention in Syria further complicates the tangled web of conflicting purposes and rival applications of extreme violence which have brought that country so low in the last four years. Even if we assume that Russian aircraft will in future target the Islamic State as well as the other rebel groups they attacked on their first missions, Russian bombing will have, if the western air effort is anything to go by, limited effect on Isis’s ability to maintain control over its core territory. While unlikely to seriously weaken Isis, Russian air support, which it is now clear they will direct at a range of rebel groups, will strengthen the Assad regime, at least in the short run, and that, absent other developments, will prolong the war and increase the suffering of civilians.

Yet the Russian move also brings an opportunity, which the United States and its allies should seize, to shift the focus of international concern about Syria away from the military extinction of Isis towards the protection of those civilians by whatever arrangements, partial though they may be, that can be achieved, with or without Moscow’s cooperation. Let us take President Vladimir Putin’s rhetoric at face value and agree that there is common ground in the attempt to contain Isis. Let there be deals to prevent possible confrontations between Russian and coalition aircraft. Let the generals confer.

But let us go beyond that to propose safe havens, no-fly zones and local ceasefires which will get an increasing number of ordinary people out of the line of fire, or at least free them from the fear of air strikes by whatever side. Let Moscow, or Tehran, explain why that would not be a good idea.

Of course, there are large practical objections to such schemes, notably that they bring military advantage to one contender or another. The fact that they have sometimes worked in the past, as in Iraqi Kurdistan after the first Gulf war, does not mean they could be easily revived now. Their feasibility, however, should be actively explored by governments and their military planners. It would be foolish to be too optimistic, but the effort should be made.

Until now the western formula has been that the welfare of the Syrian people was best served by working to destroy Isis and to remove the Assad regime, while caring for huge numbers of refugees in camps in neighbouring countries. If peace had been more attainable in Syria, this approach might have been acceptable. But it neglected the need for the protection of civilians in their own country. The failure to protect civilians in Bosnia and in Rwanda led to the emergence in 2005 of the doctrine of “the responsibility to protect”, which the United Nations formally adopted in 2009. It was supposed to be a lesson learned forever, but it seems to have been quickly forgotten in Syria.

That responsibility is one reason why the British government’s preoccupation with the idea of the RAF joining in air strikes against Syrian targets is so beside the point. A few extra bombers will make no difference to an air campaign already running out of targets. There is no overwhelming objection, but also no overwhelming requirement. There should be a collective waking up to the need for protection within Syria, and Britain should ideally use its limited influence to that end, with John Major’s Iraq initiative in 1991 as a precedent.

Of course, a true Syrian peace is still the ultimate goal. Mr Putin’s motives in Syria are multiple. He wants to distract attention from the still-unfinished adventure in Ukraine; he seeks a measure of international rehabilitation; he wants Russia to look like a great power acting boldly where the United States has failed; he looks to stand tall before Russian public opinion; and he may be genuinely worried about jihadists joining Isis and then coming back to Russia.

But if there is one thing we know about Mr Putin it is that he does not think things through. Russia may well have bitten off more than it can chew, its actions may well increase Sunni Muslim hostility toward Russia. To be even more deeply identified with the Assad regime seems unwise. Within a relatively short period of time, Moscow could be looking for an exit strategy.

If and when that happens, there could be a moment when Russian and western interests converge, a convergence which would also have to include Iran. There is a glimmer of hope in such speculation. Meanwhile, western countries should look very urgently at any initiatives which will protect civilians in Syria now, and should test Russia, and Iran, on that critical issue.