Last month, Russian President Vladimir Putin was adamant an assault on Idlib was not on the cards. Mr Putin stated that an attack on one of the last remaining rebel strongholds was "not expedient now". However, in recent days, Bashar Al Assad's forces, backed by Russian air support, have <a href="https://www.thenational.ae/world/mena/russian-ceasefire-falters-as-syrian-government-presses-idlib-offensive-1.863964">launched a significant offensive</a> in the area. Some reports claim the assault included chemical attacks, especially to the northwest, where the militant group Hayat Tahrir Al Sham, a reincarnation of the Al Qaeda-affiliated Nusra Front, maintains a significant presence. It appears that Mr Putin has had a rethink about whether attacking Idlib was expedient, which begs the question: what changed? Last September, an agreement was forged between Russia, Iran and Turkey to create a demilitarised buffer zone in Idlib province, building on an understanding that was reached between the parties in Astana in 2017. Concerned that there would be an imminent all-out attack against opposition forces, Turkey was able to convince Russia to allow Ankara to disarm or neutralise Hayat Tahrir Al Sham and other extremist groups and station Turkish military observation posts around Idlib. Russia agreed. By allowing Ankara to do the dirty work, it would save Moscow manpower, funds and the prospect of international condemnation for the inevitable loss of civilian life in an all-out assault, as had happened in other Syrian towns and cities. In the case of Douma, for example, the use of chemical weapons by the Assad regime prompted a retaliatory, if tokenistic, US airstrike against Syrian military bases. Moscow also reasoned that by pandering to Turkey’s concerns, Russia would win goodwill from Ankara and push Turkey further away from the West. For Turkey, the stakes in Idlib are high. An all-out attack by the Assad regime would mean that hundreds of thousands of Syrians could seek asylum in Turkey. Recent reports indicate that <a href="https://www.thenational.ae/world/mena/idlib-residents-defy-death-to-take-a-stand-against-assad-s-assault-1.866538">180,000 people have been displaced</a> and have fled towards the Turkish border, while others have refused government offers of safe passage. However, Turkey is already finding it difficult to cope with the estimated 3.8 million Syrian refugees it currently hosts, especially as the country struggles to deal with an ongoing economic downturn. The fall of Idlib would also effectively mean an Assad military victory in the eight-year long civil war would be all but assured. This would put pressure on Turkey to withdraw from Afrin and other areas to the west of the Euphrates. Turkey has held these territories, together with its proxy the Free Syrian Army, since embarking on Operation Euphrates Shield and Operation Olive Branch in 2016 and 2018 respectively. These interventions were launched to wrestle territory away from the US-backed Syrian Democratic Forces (SDF), which is dominated by the Kurdish-led People’s Protection Units (YPG). Ankara claims the YPG is affiliated to the outlawed Kurdistan Workers’ Party (PKK), which has waged a bloody separatist war against Turkey since the 1980s and is deemed a terrorist organisation. Russia's earlier decision to hold off from a major offensive proved fruitful. By restraining Mr Al Assad in Idlib, Moscow managed to get Turkey on side, cause a major rift inside Nato and drive a deeper wedge in the already strained relationship between Turkey and the US. Ankara has reaffirmed its commitment to purchase the <a href="https://www.thenational.ae/opinion/comment/turkey-s-commitment-to-the-russian-s-400-missile-system-is-ideological-not-practical-1.857855">S-400 missile defence system</a> and Turkey has even sent personnel to Russia for training to learn how to operate S-400s, despite them being incompatible with Nato hardware. However, in recent weeks Russia has become increasingly frustrated. Turkey has yet to disarm or neutralise Hayat Tahrir Al Sham and other militant extremist groups. Moscow is concerned that Turkey is either unwilling or unable to do so and is therefore piling on the pressure. In a desperate bid to hold onto its influence, Ankara has <a href="https://www.thenational.ae/world/mena/turkish-arms-bolster-syrian-rebels-on-frontlines-of-russian-backed-assault-on-idlib-1.866220">increased its arming</a> of aligned rebel groups in Idlib. However, a headache for Turkey would be if the groups it backs join forces with Hayat Tahrir Al Sham. That was reportedly the case in Kafr Nabuda, where opposition forces retook the town from the regime. Russia is also concerned that Turkey might eventually waver in its commitment to purchase S-400s, especially if the US were to dangle carrots in front of Ankara. Perhaps Turkey might be swayed by the possibility of receiving discounted Patriot surface to air batteries, a Nato-compatible alternative to the S-400, or assurances from the US that any buffer zone between Turkey and Syria would be cleared of SDF troops, whom it has been supplying with weapons and training. Turkey is trying to organise talks with US officials and there have even been reports that Turkish President Recep Tayyip Erdogan might meet US President Donald Trump next month. As has often been the case in Syria’s devastating war, local battles have greater ramifications for world powers. The future of Idlib is no exception. Idlib is Moscow’s ultimate trump card, to ensure that Turkey’s international orientation remains close to the Russian orbit and away from the West. Moscow knows that at least for the time being, Turkey has much to lose if Idlib were to fall. <em>Dr Simon Waldman is a visiting research fellow at King’s College London and the author of The New Turkey and Its Discontents</em>