اقرأ باللغة العربية After the Turkish army mobilised troops and heavy equipment to its northern border with Syria, for the first time since the start of the conflict in the country six-and-a-half years ago Turkey has invaded Syrian territory. Turkish troops reached Idlib in northwest Syria this week, which is under the control of the Syrian opposition, putting the nearby city of Afreen under siege to prevent Kurdish People's Protection Units (PPUs) from advancing to the Turkish border. Turkish troops advanced inside Syria and established observation posts to monitor Kurdish movements and block the PPUs from advancing to take control of northern Syria or unilaterally declare self-rule in the region. The Turkish move was welcomed by some in the Syrian opposition, especially those with links to Turkey such as the Coalition of Syrian Opposition Forces and Turkey-based military factions. However, it was criticised by others as yet another form of foreign intervention in the country and similar to that of Russia and Iran. The regime led by Syrian President Bashar Al-Assad described Turkey's incursion into Idlib as “flagrant aggression” and demanded that the troops withdraw. It seems to have overlooked the fact that Russian and Iranian intervention, as well as that by the Lebanese Shia group Hizbullah and Iraqi sectarian militias, has also been flagrant aggression and violations of state sovereignty. The Turkish invasion came a few days after talks between Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan, after which the latter declared Turkish troops would soon enter Syria and deploy according to a plan discussed with Putin to “ease the escalation” in the region. The Turkish troops would remain in Idlib, he said, and Russian forces would remain on the perimeter, meaning that the Turkish military intervention has been approved and supported by the regime's top ally even though Damascus claims it rejects the invasion. Idlib is one of four regions of the country where de-escalation was agreed in May at the Astana Talks sponsored by Russia and Iran, allies of the regime, and Turkey, a supporter of the opposition. Opinions differ about the real reasons behind the Turkish operation in northern Syria supported by Russia. Russian analysts say it is part of an agreement reached in Astana between the regime and the opposition, sponsored by Russia, Turkey and Iran, and that the Turkish troops will move on the ground under Russian air cover to eradicate the Al-Sham Liberation group, formerly the Al-Nusra Front, and to create safe conditions for a ceasefire in the area. The Kurds claim that Turkey's goal is to expel them from a region that is currently under their control and prevent them from annexing the northwest part of Syria to their hoped-for future West Kurdistan. The Syrian opposition close to Turkey argues that the goal is to empower the opposition in this area of Syria in order to help it take control on the ground. Some in Ankara suggest that the goal is to prevent the Kurds from reaching the Mediterranean, because Kurdish control of Idlib would not only provide the Syrian Kurds, but also their Iraqi neighbours, with access to the Mediterranean Sea. Without this access, Syrian and Iraqi “Kurdistan” would remain beholden to neighbours Iran and Turkey. Blocking Kurdish access to the Mediterranean is a priority for Ankara, and Erdogan and the ruling Turkish Justice and Development Party (AKP) are in dire need of a military victory, however small, to improve their political standing. Iranian analysts allege that Ankara's goal is to strengthen the Turkish military position in Syria so it can have a larger share of the spoils after the conflict is settled. Tehran believes that Ankara wants to protect the Turkmen minority in northern Syria, which in April called for a safe zone to be set up in the strategically important province of Idlib. Irrespective of the statements by the countries involved, the truth is that the Turkish incursion has two main goals. The first is Turkish and is to drive a dagger into Kurdish efforts to create a Kurdish entity in northern Syria. The second is Russian and is to eliminate the last and largest opposition stronghold and so end the war in favour of the regime. Turkey also wants to stop Idlib from becoming another Aleppo, which was pummelled by Russian air strikes under the pretext of fighting the Al-Nusra Front and other groups. The city was decimated as a result, and if something similar happens in Idlib it could create an unprecedented humanitarian crisis on the border with Turkey, with millions of people trying to flee the country. This would further aggravate the Syrian refugee problem, especially as Idlib has 2.4 million residents and 1.3 million refugees. Russia is most likely trying to neutralise Idlib over the coming weeks or months until the Syrian regime has finished fighting in Homs and Deir Al-Zor and is ready to turn its attention to northwest Syria. Ankara would then face even more difficult choices, the least of which could be participating in a military campaign against radical groups, including Sham Liberation which has thousands of members. Turkey continues to deny that it has any direct contact with Al-Assad, saying that it believes the Syrian Kurds are a more serious threat to its national security than the Al-Assad regime. Meanwhile, the Syrian opposition is concerned that Turkey's presence in Idlib will act as a bridge for the regime to recover the city and restore relations with Ankara. Forward forces of the Turkish army entered Idlib under the protection of Sham Liberation fighters, who perhaps understood the danger they were in. Regime and Iran-backed militias have already opened corridors for Islamic State (IS) group fighters to advance towards Idlib without resistance, inviting them to attack the Sham Liberation group. The Iranians want to see Turkey bloodied by fighting jihadists in Idlib, and for this reason it has opened the path for the IS fighters. Even if Turkey emerges unscathed, Turkish control of Idlib would be better for Iran than the Kurds, since the Kurdish demands also represent a problem for Tehran. Some leaders of Sham Liberation want to fight Turkey to the end even if this means forging an alliance with IS. For the Turks themselves, containing and not clashing with Sham Liberation is the best available option, since they will want to avoid getting embroiled in Russian plots to ensnare Turkey in a war of attrition. The US position is ambiguous. It is uneasy about the Turkish military incursion and concerned about blocking its Kurdish ally's access to the Mediterranean Sea, thus circumventing any economic siege by Turkey, Iran and Syria. However, it can still call Turkey out at any time under the pretext that Ankara is coordinating with the terrorist group Sham Liberation, several of whose leaders are on its most-wanted list. The Syrian regime has its hands tied, and statements by senior Russian officials have revealed that it knew nothing in advance about the Russian-Turkish-Iranian deal that allowed Turkish troops to invade northern Syria. The Turkish military intervention in Syria sends out messages to all sides. It could be a way of calming northern Syria and preventing Idlib from suffering the fate of Aleppo. Or it could simply expedite its destruction.