Fragile countries have collapsed into civil war and flailing politicians have proved incapable of stopping the mayhem

The battle for Aleppo now seems all but ended, though it is by no means certain that the Syrian Civil War is drawing to a close. But this stage of it seems over, and the reaction of the world is one of horror, despair and frustration. Over all news outlets there is broad agreement: the destruction of eastern rebel-held Aleppo is a human catastrophe, and no one in Europe and America has been able to stop it happening.

Indeed the horrified reaction is easy to understand. Aleppo now looks like Stalingrad or one of the reduced to rubble German cities in 1945. All that was meant to be in the past. It seems that we have learned nothing from our history – certainly not how to prevent it repeating itself.

Pope Francis is in the unhappy position of having to send the nuncio to Syria to plead with President Assad, asking him to spare the fallen city at this late hour. Of course, this is precisely the opposite of what Mr Assad has in mind. Now that the rebel enclave is collapsing, this is his opportunity to rub out and destroy those fighters who have resisted him so long. The last thing he is ever going to do is to give those fighters the chance to fight another day. Nor is Mr Assad suddenly going to turn into an exponent of peace and reconciliation. That has never been the Assad way. At stake for him is the future of the regime he heads, and that depends on neutralising present and future opposition. Aleppo today is a rerun, though on a vaster scale, of what his father did to Hama in 1982. That piece of brutal suppression supposedly won the regime nearly three decades of peace; they must hope that Aleppo and the other ruined cities of Syria will do something similar. Victory seems in sight, and they are not going to stop now. State-sponsored violence has always been the Assad stock in trade; honest supporters of the regime admit as much, claiming that this is the only way a country like Syria can be governed.

So, what went wrong, and how could it all have been prevented? The first thing that went wrong, perhaps, was that our sympathy with the rebels was misplaced. There has been a tendency to divide the rebels into the good and the bad; in the latter category come ISIS and Al-Qaeda, and in the former the sort of rebels we could work with – except this latter category turned out to be rather elusive. There are no doubt “good” rebels inside Syria – the Kurds come to mind – but their chances of replacing the regime are nil; and the Kurds are fighting for limited objectives, rather than the overthrow of the Assad regime. Whoever the rebels are, it is important to realise that they are just as committed to using violence to achieve their aims as is the regime, though the means at their disposal may be different. The reason that a negotiated settlement has been so difficult is because most parties were simply not interested in negotiation. Negotiation will only come, one suspects, when all parties have fought themselves to the point of utter exhaustion.

Given their commitment to violence, one way the West went wrong was to allow third parties to arm the various fighting factions. A great many British-produced weapons, one may surmise, ended up in the hands of various rebel groups, including ISIS. And we know that the regime is dependent on Russian firepower and Iranian manpower. How the West could have prevented the involvement of Russia and Iran is difficult to say (perhaps a more robust approach in Ukraine would have helped); but we could certainly stop selling arms to the Gulf monarchies and Saudi Arabia. That we did so may well have extended the war, without changing its outcome.

In recent times we have seen a series of fragile countries collapse into sectarian civil war: Lebanon, Somalia, Congo, Yugoslavia, Rwanda, Iraq, Algeria, Sudan and Syria. There may well be others that will follow the same path. Some have recovered, while remaining fragile; others are failed states. But one thing is certain: the world has not learned how to deal with these tragic situations. What went wrong, how could it all have been prevented? If only we knew.