Given the mayhem in Syria — where death, destruction and displacement are routine — nothing shocks us any more. We have seen chemical weapons used, children tortured, refugees starved to death; we have watched the Syrian state collapse and neighbouring countries destabilised. Few expect the disintegration to stop. Ask diplomats or analysts about Syria these days and you are likely to hear predictions of several more years of war and fragmentation. And yet there are still moments in the crisis, which will soon enter its fourth year, that have so much destructive potential that they should shock us — and force us to recognise how badly adrift western policy on Syria has been.

A crucial moment came earlier this month when a collection of fighters known as the Islamic Front seized control of weapons depots and the headquarters belonging to rival rebels backed by an international coalition of western and Arab states. The US and Britain promptly responded by suspending non-lethal aid to rebel-held northern Syria, amid concern that it would end up in radical hands, if it had not done so already. Selim Idriss, the western-backed chief rebel commander, and the Syrian National Coalition, the main political opposition group, tried to dress up the incident in less dramatic terms, claiming they had requested the Islamic Front’s help when their people were attacked by Al Qaida groups. In reality, though, the seizure of the equipment and headquarters was an attempted coup against the coalition. It was also the unravelling of the policy of western governments that have backed it. There is no denying today that whatever small influence the moderate rebels once had on the ground (and it was never much) is fast evaporating.

The moment is more disturbing when you take this into account: Those who have facilitated the finance and arming of the Islamic Front are members of the same foreign alliance that backs the coalition — Qatar, Turkey and Saudi Arabia. The three countries had been urged, time and again, by their western partners to channel funds and weapons only through Idriss. They have never listened. With a US-Russia sponsored peace conference on Syria planned in Switzerland next month, surely the illusion that any diplomatic progress can be achieved has been shattered — not that there was much hope to begin with. The idea of Bashar Al Assad, the Syrian strongman, agreeing to hand power to a transitional authority (the basis of the peace conference) was never persuasive, especially when the momentum on the ground has been moving, even if only slightly, to his advantage.

On the other side, meanwhile, the most lethal actor among the rebels is now the Islamic State of Iraq and the Levant, which is the main Al Qaida group. Its principal competitor is the Islamic Front, not Idriss’s Free Syrian Army. Idriss has been on a damage-control mission to recuperate the captured equipment and ease the fractures among the rebels. His allies within the Syrian opposition, meanwhile, have been arguing that the Islamic Front, being one of the strongest forces on the ground, should have contact with foreign powers and, indeed, a seat at the table at the Switzerland conference.

There are some relatively moderate groups within the Islamic Front that western governments can deal with — not long ago they happily worked under Idriss. US diplomats have been trying to persuade them to back, or at least not publicly oppose, the peace conference. They have no problem including them as part of the opposition delegation to the peace talks. Others, however, notably the large brigade known as Ahrar Al Sham, are beyond the pale for the US, which considers them to be too close to the jihadists of Al Qaida.

In theory, including groups with fighting power will make for sensible policy. It is not clear, though, why the rebels will bother to take part in a diplomatic process that has so little prospect of a breakthrough. Nor can they count on diplomatic inclusiveness to deliver them what they want most — more money and weapons. Moreover, in a fluid rebel movement where allegiances rapidly shift, and groups fight each other one day and cooperate the next, brigades that can appear cooperative now can later become less accommodating.

Watching the muddle of northern Syria from his Damascus base, Al Assad is undoubtedly (and unfortunately) satisfied. Today, he can claim more credibly that the unruly rebels fail to offer an alternative to his rule, no matter that it was his brutal killing methods that contributed to radicalising and splintering the opposition. The Syrian National Coalition that sought to be the political face of the rebel movement never had a chance to play the role of the alternative or, as it is designated, the representative, for the Syrian people. Its survival — and its very relevance — depended from the start on whether it could deliver the western help it promised to Syrians.

After many months of denial, it is plainly clear to the coalition that the West can deliver nothing substantive on the military front and barely any coherence on the diplomatic front. Just like the coalition they back, the US and its western partners have very little influence over what happens in Syria.

— Financial Times