There was an alternative. It is worth bearing this salient fact in mind as we survey the catastrophe that Syria has now become; 93,000 deaths according to the latest UN figures, which are widely believed to be conservative. It would be wrong to blame the west’s failure to intervene wholly on Barack Obama, an otherwise exceptional president made too cautious about intervention by learning the wrong lessons from Iraq. Our own leaders too have failed to exert the pressure on the US president which both Kosovo and Libya have shown can succeed in tipping the balance towards intervention.

The question of how we got here is one for future generations to mull over, much as we now look back on the Major government’s calamitous failure in Bosnia in the 1990s; for now, we are left with the question of how to deal with the fallout of our own disaster. This question has come to revolve not around anything so grand as a Libya-style no-fly zone, let alone the commitment to putting boots on the ground that helped force Milosevic to give way in 1999, but rather on the meagre question of giving arms to the rebel forces.  This too has provoked major opposition.

It is easy to dismiss the so-called ‘anti-war left’ – in reality, they are neither, for they actively oppose ending wars and there is nothing left-wing about permitting the slaughter of the powerless by the powerful. It is less easy, however, to dismiss the strong counter-arguments made by those such as Stephen Bush who have championed intervention in the past and well understand that inaction is also a decision. Even staunch interventionists such as John Rentoul and Norman Geras are deeply uncertain as to the correct path forward. Certainly, the decision over whether to arm rebels with undoubted links to Islamist terror groups is a far more difficult one than simply saying, as is now painfully obvious, that we should have done something a year ago.

On balance, however, I think that we must resolve this by asking what it is that we want in Syria. The fall of Bashir al-Assad was once treated as inevitable and yet it now appears ever less likely. Even if he were to be toppled, the rebel government that would take his place would be one angered at our persistent failure to do more than offer platitudes about red lines, and radicalised by the radical Islamists who have filled the vacuum left by our failure to help. With a clear ‘win’ by either side either undesirable or unlikely, we are forced to look to the scarcely more plausible outcome of some form of negotiated settlement. Vladimir Putin’s recent remarks at the G8 even indicate that it may yet be possible to depose Assad himself in such a deal, clearly a victory for opponents of the regime. Yet if this proves impossible, then the ‘least worst option’ may very well involve Assad retaining power in some form that may be morally unacceptable to us, but would be a consequence of our own decisions in the last two years.

At present, however, there is no reason for Assad to come to the bargaining table for even so limited a settlement. His regime remains well supplied by its allies in Iran and Russia. He knows that the west will not interfere. And he knows that he is now winning the war and that the fall of the rebel stronghold of Aleppo is imminent. Absent some unexpected events on the ground, the only reason he would have to bargain would be if outright victory became too costly and if there looked to be some way he could reach a settlement that did not involve his own ousting. With no political will for anything stronger and uncertainty as to whether it could even work, arming the rebels and creating a more level killing field has thus become the only remotely plausible way of preventing his complete triumph and  forcing a deal.

Even this, however, carries with it considerable danger. It is perfectly fair to query how many of the arms that we supply to the Syrian rebels could one day be turned on us. It is also perfectly fair to fear that the rebels are now irreversibly in thrall to jihadism – even if it is grating to hear these arguments coming from those who opposed doing something before those extremists could become so powerful within the rebel movement. Yet as far as we can tell, the worst elements of the rebels are already getting arms and it is the moderates who are being left powerless. Furthermore, if the main alternative is the victory of Assad – and it is – then it is hard to see how that is any better, with his radical Hizbullah support already benefitting from new arms and resources, and a more sympathetic ear than ever in Damascus.

Ultimately, there are now only two plausible ways that the conflict in Syria can end; either Assad destroys the rebels and continues to brutally govern his ever more unstable state in a more repressive manner than ever, or else he is forced to come to some form of settlement. There is no third way. The west must decide which of these two paths it wishes to embark upon and it must decide now. If our own failure has meant that neither seems to offer much hope, then we can at least try to choose the lesser of two evils now and make up for a small part of the damage we have caused.