The Syrian armed forces are close to capturing the remaining rebel-held districts in the enclave of east Aleppo, bringing them their biggest victory in five years of war. The insurgent armed forces, that were originally estimated to number between 8,000 and 10,000 fighters, have been retreating or giving up more readily than had been expected. It is still possible that a hard core will hold out in the ruins, but President Bashar al-Assad will be eager to crush any remaining resistance so he can present the fall of east Aleppo as a decisive turning point in the conflict.

Will this be true? There are so many players with such diverse agendas in the Syrian civil war that past “turning points” have turned out to be no such thing. But what is truly important about what we have just seen in Aleppo is that the outside allies of the armed opposition to Assad – Turkey, Saudi Arabia, Qatar and, in a somewhat different category, the US - have not come to the rescue of the rebels whom they have previously supported.

Over the last five years it has been foreign powers and not domestic parties in Syria who have dictated who is winning or losing at any particular moment. When Assad was losing he went to the Russians, Iranians, Iraqis and Hezbollah and asked for more support. Likewise, the insurgents looked to their external allies when they were on the retreat. This time round this has not happened. The Russian military intervention in September 2015 finally and permanently tipped the balance of power Assad’s favour.

Video shows Syrian Army taking Aleppo

Turkey, unsupported by any foreign power and enmeshed in its struggle with the Kurds and Islamic State, has been largely mute about the fate of east Aleppo. Its main concern is the de facto Syrian Kurdish state that stretches across northern Syria just south of its frontier. The failed military coup of 15 July and the consequent purge makes it dubious how far President Recep Tayyip Erdogan can effectively intervene at this stage in the war.

Saudi Arabia took over in 2013 from Qatar as the biggest Arab ally of the insurgency. Until quite late in the day, the Saudis and the Arab Gulf states remained convinced that Assad would be defeated and overthrown like Muammar Gaddafi in Libya in 2011. They exaggerated the likelihood of US military intervention against Assad though President Obama had made clear his wish not to be sucked into another quagmire in the Middle East after the US experience in Iraq and Afghanistan.

In Pictures: The crisis unfolding in Syria Show all 30 1 /30 In Pictures: The crisis unfolding in Syria In Pictures: The crisis unfolding in Syria A Syrian family arrives at a checkpoint, manned by pro-government forces, at the al-Hawoz street roundabout, after leaving Aleppo's eastern neighbourhoods Getty In Pictures: The crisis unfolding in Syria A Syrian woman, fleeing violence in the restive Bustan al-Qasr neighbourhood, reacts as she stands with her children in Aleppo's Fardos neighbourhood, after regime troops retook the area from rebel fighters Getty In Pictures: The crisis unfolding in Syria Syrian pro-regime fighters, gesture as they drive past resident fleeing violence in the restive Bustan al-Qasr neighbourhood, in Aleppo's Fardos neighbourhood Getty In Pictures: The crisis unfolding in Syria Syrian rebels withdrew from six more neighbourhoods in their one-time bastion of east Aleppo in the face of advancing government troops, the Syrian Observatory for Human Rights said Getty In Pictures: The crisis unfolding in Syria Syrian rebels withdrew from six more neighbourhoods in their one-time bastion of east Aleppo in the face of advancing government troops, the Syrian Observatory for Human Rights said Getty In Pictures: The crisis unfolding in Syria Syrian residents, fleeing violence in the restive Bustan al-Qasr neighbourhood, arrive in Aleppo's Fardos neighbourhood , after regime troops retook the area from rebel fighters Getty In Pictures: The crisis unfolding in Syria Syrian pro-regime fighters, gesture as they drive past residents fleeing violence in the restive Bustan al-Qasr neighbourhood, in Aleppo's Fardos neighbourhood Getty In Pictures: The crisis unfolding in Syria Syrian residents, fleeing violence in the restive Bustan al-Qasr neighbourhood, arrive in Aleppo's Fardos neighbourhood, after regime troops retook the area from rebel fighters Getty In Pictures: The crisis unfolding in Syria Syrian residents, fleeing violence in the restive Bustan al-Qasr neighbourhood, arrive in Aleppo's Fardos neighbourhood Getty In Pictures: The crisis unfolding in Syria A Syrian pro-regime fighter speaks with a child, as residents flee violence in the restive Bustan al-Qasr neighbourhood. Syrian rebels withdrew from six more neighbourhoods in their one-time bastion of east Aleppo in the face of advancing government troops AFP/Getty Images In Pictures: The crisis unfolding in Syria Smoke rises as seen from a governement-held area of Aleppo, Syria Reuters In Pictures: The crisis unfolding in Syria Syrian soldiers targeting rebels-held areas in the eastern neighborhoods in Aleppo, Syria. According to media reports, the army is now holding on 99 percent of Aleppoís eastern neighborhoods EPA In Pictures: The crisis unfolding in Syria Syrian pro-government forces patrol Aleppo's eastern al-Salihin neighbourhood after troops retook the area from rebel fighters Getty In Pictures: The crisis unfolding in Syria Syrian soldiers rest following the battle at al-Sheik Saeed neighborhood in Aleppo, Syria EPA In Pictures: The crisis unfolding in Syria A Syrian pro-government fighter walking past closed shops in the Bab al-Nasr district of Aleppo's Old City. Once renowned for its bustling souks, grand citadel and historic gates, Aleppo's Old City has been rendered virtually unrecognisable by some of the worst violence of Syria's war Getty In Pictures: The crisis unfolding in Syria The crucial battle for Aleppo entered its 'final phase' after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad Getty In Pictures: The crisis unfolding in Syria Syrian civilans arrive at a checkpoint, manned by pro-government forces, at the al-Hawoz street roundabout, after leaving Aleppo's eastern neighbourhoods. Syria's government has retaken at least 85 percent of east Aleppo, which fell to rebels in 2012, since beginning its operation Getty In Pictures: The crisis unfolding in Syria Syrian civilians flee the Sukkari neighbourhood towards safer rebel-held areas in southeastern Aleppo Getty In Pictures: The crisis unfolding in Syria Syrians celebrate in the government-held Mogambo neighbourhood of the northern Syrian city of Aleppo, after rebel fighters retreated into a small pocket of their former bastion in the face of new army advances Getty In Pictures: The crisis unfolding in Syria Syrians celebrate in the government-held Mogambo neighbourhood of the northern Syrian city of Aleppo, after rebel fighters retreated into a small pocket of their former bastion in the face of new army advances. The fall of Aleppo would be the worst rebel defeat since Syria's conflict began in 2011, and leave the government in control of the country's five major cities Getty In Pictures: The crisis unfolding in Syria A Syrian refugee camp in the Bekaa Valley, Lebanon, close to the Syrian border PA wire In Pictures: The crisis unfolding in Syria Syrian refugee Aliya inside the tent where she lives with her husband and ten children in a camp in the Bekaa Valley, Lebanon, close to the Syrian border PA wire In Pictures: The crisis unfolding in Syria Syrian refugee women and children outside the entrance to their tents in the refugee camp in the Bekaa Valley, Lebanon, close to the Syrian border PA Wire In Pictures: The crisis unfolding in Syria A Syrian refugee camp in the Bekaa Valley, Lebanon, close to the Syrian border PA wire In Pictures: The crisis unfolding in Syria A Syrian refugee camp in the Bekaa Valley, Lebanon, close to the Syrian border PA Wire In Pictures: The crisis unfolding in Syria A Syrian refugee woman outside the entrance to the tent where her family live, in the refugee camp in the Bekaa Valley, Lebanon, close to the Syrian border PA wire In Pictures: The crisis unfolding in Syria A vehicle drives past a mosque at night in Idlib, Syria. Picture taken with a long exposure Reuters In Pictures: The crisis unfolding in Syria Damaged buildings stand in the rebel-controlled town of Binnish in Idlib province, Syria Reuters In Pictures: The crisis unfolding in Syria The night sky is seen through damaged windows in the rebel-controlled town of Binnish in Idlib province, Syria Reuters In Pictures: The crisis unfolding in Syria Damaged buildings stand in the rebel-controlled area of Maaret al-Numan in Idlib province, Syria Reuters

In reality, Assad was always likely to stay in power because the upper ranks of his regime were united, he had a powerful army but, above all, because Russia and Iran were always more committed to his survival than Turkey, Saudi Arabia, Qatar and the US were to regime change.

But there are limits to Assad’s military success. This has been underlined by the recapture of the ancient city of Palmyra by Isis fighters who are once again executing captured Syrian soldiers in the streets of the modern city. The Syrian army, like all other combatants in the Iraq-Syrian civil war, is short of troops to replace casualties. This is one reason why men of military age leaving east Aleppo are being conscripted straight into the army.

The conflict was and remains a civil war, primarily sectarian between Sunni and the rest but with ethnic and social aspects. The Syrian security forces may have taken the poorest and most religious part of Aleppo, but the countryside around Aleppo is largely Sunni. Better off urban areas tended to support the government, while the rural Sunni districts are the bed rock of the revolution.

Seven-year-old girl tweeting from Aleppo siege pleads for help