How will we regard the war in Syria in 30 years’ time – assuming it’s over by then, which is quite an assumption? (The war in Lebanon, a country similarly divided by sect but much smaller, lasted 15 years.)

We tend to look on conflict in moral terms these days – which side commits more atrocities? We have gone back to St Thomas Aquinas and the “just war” theory. After failure in Bosnia and Rwanda in the early 1990s – where the world looked on as genocide took place – the UN developed the doctrine of “responsibility to protect” (R2P). The prime minister uses this language when urging further involvement in Syria.

It’s undeniable that the Assad regime has committed horrendous atrocities – far more than the rebels. The merciless onslaught on Babr Amr, a rebel-held suburb of Homs in 2012, documented in Paul Conroy’s new book Under the Wire, is evidence enough.

Yet most western governments and people are reluctant to get involved because of the mess in Iraq, where the US invasion turned a bad but stable situation into out-of-control violent chaos, and the aftermath of Libya, where intervention dislodged a dictator but left a void where the state should be.

17 cameronputin r w Why Syrias conflict is turning from a just war into a cold war

These are practical, not ideological, objections. But now we have a new element: is this a new cold war? President Putin of Russia (above right, with David Cameron) is providing Bashar al-Assad with weapons and diplomatic support, while a reluctant President Obama says he’ll send arms to the rebels. So is a moral struggle morphing into a power play?

Sadly, I think it is. The Middle East is changing shape, with sectarian and diplomatic loyalties trumping any kind of morality. The misplaced confidence of western governments (how often have we heard in the last two years that Bashar al-Assad was about to fall?) only encouraged his backers, Iran and Russia, to provide more support.

The Americans thought that Assad’s fall would provide them with a quick and easy incidental victory over Iran. Such wishful thinking. Assad’s survival has become a boost for Iran. The new cold war looks like this: Russia, Iran and Iraq back Assad. The west plus Gulf states, Jordan and Turkey back the rebels. Sectarianism – the countries backing Assad are Shia, the ones backing the rebels are Sunni – is being inflamed by old enmities from Europe after WWII.

I wish I had a solution. I just keep thinking about Africa in the 1980s. Nowadays we look on the struggle against apartheid as a moral battle. So it was, but why did apartheid South Africa crumble in 1989? Partly because the economy was foundering under sanctions and those who struggled for racial equality had won the argument, but mainly because the cold war was over.

It was the year the Berlin wall came down. The west had no more reason to back (however shame-facedly and covertly) the apartheid regime, because the ANC could no longer be seen as a Trojan horse for communism. Communism – at least in its powerful, Soviet style – was over. Mozambique, Angola, Ethiopia – country by country cruel, pointless proxy civil wars ground to an end. It was no longer in the interest of capitalists or communists to stir up the tribal, racial and variously venal motivations the various sides had for fighting each other.

So I wonder if outside forces will be more important than the internal dynamic in bringing the conflict in Syria to a close. This war could run and run, pitting Sunni and Shia against each other across the region, but maybe the best thing the west could do is try to sort out its deteriorating relationship with Russia.

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