What's the reason behind the recent escalation of Syria's war?

When Turkey launched Operation Olive Branch to clear Afrin of the YPG on January 20, the Syrian regime intensified its ongoing offensive in the northwestern province of Idlib, the final urban stronghold of the Syrian opposition in the north. Backed by its closest allies—Russia, Iran, and Lebanon’s Hezbollah—the regime advanced across the province, even though it is one of the four designated de-escalation zones that was agreed upon by guarantors Russia, Iran, and Turkey. 

Now, about three weeks into Turkey’s operation in Syria’s Afrin, the situation on the ground has seen several developments. 

US-trained and armed YPG militants in northeastern Syria have transferred to Afrin via Iran and regime-controlled territories as reinforcements to fight against Turkey, which is a NATO member and US ally.

Meanwhile on Thursday, Iran-backed regime forces came under air and artillery fire from the United States and the YPG in a move that the US said was in “self defence”.

During this period, Syria’s Idlib and Eastern Ghouta saw a surge in violence from the regime, while the region overall saw an increase in diplomatic traffic involving leaders of the various countries involved in Syria.

YPG “reinforcement” in Afrin

YPG militants have been moving from the east of the Euphrates Shield region, like Manbij and Kobani, where there is a permanent US troops presence, to Afrin as reinforcements to fight against Turkey's military operation.

Their numbers could grow, according to a US defence official who spoke the Wall Street Journal. 

US officials said they told the YPG that Washington would not support units moved to Afrin to fight against Turkey, but still allowed for the militants, who they trained and armed, to transfer to fight their NATO ally.

Because the Euphrates Shield region is between Manbij, Kobani and Afrin, the militants were transferred through regime-and-Iran controlled territory just south of the Euphrates Shield zone, to enter Afrin.

A number of statements came from Tehran after Turkey's Afrin operation began, calling Turkey to prevent any escalation with the regime and to immediately withdraw after the operation ended.

The US’ support of the YPG, later renamed the Syrian Democratic Forces (SDF), has been one of the key fission points in Turkey-US relations. The YPG is the Syrian branch of the PKK, a designated terrorist organisation in Turkey, the US and by the European Union. The US provision of heavy weaponry, tanks, logistics and strategic support for the terror group have raised tensions between the allies to an all-time high. 

The US-backed YPG now controls nearly a quarter of the country.

The US announcement of the creation of a 30,000-strong border army consisting of YPG militants crossed a final line for Ankara, which started the Afrin operation days later. 

The YPG has been launching rockets across the Turkish border targeting, killing and wounding civilians of in both Turkey and Syria.

US National Security Advisor H. R. McMaster and Secretary of State Rex Tillerson will visit Ankara in the coming days to discuss the Afrin operation. The announcement comes after Ankara made several calls for the US to leave Manbij, as it planned a follow-up operation in the strategic city about 30 km south of the Turkish border. But the same day, with the announcement from US State Department, some high-level US military officials shared pictures from Manbij with the YPG militants.

The YPG in Afrin area which is under Russian control, unlike the YPG/SDF in northeastern Syria, explains why the US said they did not have any support from the Pentagon.

US clashes with the regime 

While the US co-operated with Iran-backed regime forces in northern Syria for the transfer of YPG militants to Afrin, they clashed in the eastern town of Khusham in Deir Ezzor province, where 100 regime and pro-regime forces were killed on Wednesday by the US and YPG attacks.

“Pro-regime forces initiated what appeared to be a co-ordinated attack on Syrian Democratic Forces east of the Euphrates River deconfliction line,” Pentagon spokeswoman Dana White said during a Pentagon briefing. 

“After 20 to 30 artillery and tank rounds landed within 500 meters of the SDF headquarters location, the SDF, supported by the coalition, targeted the aggressors with a combination of air and artillery strikes."

A member of parliament in Russia said that the US-led coalition strike was an “act of aggression,” according to the Interfax news agency, showing escalating tensions between the parties.

In Khusham, regime forces are reinforced mostly by Iranian-backed militias, which are uncomfortable with the existence of US-backed forces in the area, and are trying to take steps in a bid to control the oil fields there.

Iran’s self-assertion

As Turkey prepared to construct a fourth observation post in Al Eis town of Idlib as part of the de-escalation deal, on January 29, Turkish convoy in the region came under rocket and mortar attacks.

The Turkish army said in an official statement that it was targeted by a "separatist terror organisation" by a car bomb, while it was moving in northern Idlib.

Iranian-backed militias also had been moving towards the west to claim more territory.

The attack, which killed a Turkish serviceman and wounded two others, came as a surprise, considering Turkey, Russia and Iran's co-operation and roles as guarantors in Syria’s de-escalation zones. A day later, Russian President Vladimir Putin called his Iranian counterpart Hassan Rouhani to discuss the situation in Idlib.

After the second attack on Turkish convoy in western Aleppo on February 5, Turkish Foreign Minister Cavusoglu visited Tehran. Later, Cavusoglu met with Rouhani. After their meeting, the Iranian president's office released a statement, saying that Cavusoglu had told them Turkey aimed only to fight against terrorist groups [the YPG] in Syria, and had underlined the importance of the country's territorial integrity.

Iran and Turkey have backed opposing sides in the Syrian war since the beginning, but have co-operated under the Astana talks which started at the end of 2016, along with Russia, to help bring an end to the war. 

Russia has also increased its already-intense air strikes in the south of Idlib, in civilian areas including refugee camps, in retaliatory attacks after the Free Syrian Army (FSA)-affiliated Jaysh al Nasr group claimed credit for a Russian plane being shot down in the province. Turkey had long called on both Russia and Iran to respect the de-escalation agreement in Idlib.

Six-day after the downing of the plane, Turkish President Recep Tayyip Erdogan and his Russian counterpart Putin agreed during a telephone conversation on Thursday that Ankara will continue its airstrikes against YPG militants.

Shaping the geopolitical endgame

While the regime continued its brutal offensive in northwestern Syria and its siege and starvation tactics in Eastern Ghouta, as well as its several alleged chemical attacks in the same regions, fighting in other parts of Syria had mostly slowed down, with the various groups preparing to consolidate their power. 

The conclusion of the Syrian National Dialogue Congress hosted by Russia on January 31 with a final statement regarding respect for the territorial integrity of Syria and a constitutional committee, was that it further signalled a slow approach to a political conclusion. With Russia and Iran having the upper hand on the ground against the armed opposition now, key figures from the opposition have refused to attend the Russia-backed talks.

The Russia, Iran and Turkey-backed ceasefire talks in Astana had originally begun to complement the UN-backed peace and political transition talks in Geneva. However, Russia spearheaded and eventually hosted the talks that provided the first steps towards a political solution.

The regime and its Russian and Iranian allies, as well as the US, are taking action in this political context, in final attempts to secure their interests as the war potentially draws to an end.

It is also in this context that Turkey launched Operation Olive Branch to secure its borders against the YPG.

Turkey’s biggest security concern is that the group could carve out an autonomous territory near its border, leaving Turkey vulnerable to future attacks or territorial claims.

The leaders of Turkey, Russia, and Iran will hold a trilateral meeting on Syria in Istanbul, which was announced on Thursday after President Erdogan and his Russian counterpart held a phone conversation about the latest situation in Syria.