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Turkey's Operation Peace Spring began on Wednesday with the deadly bombardment of northern Syria before thousands of Syrian fighters, backed by armour and air cover, moved across the border into Kurdish-controlled territory.

Aimed at creating a 150km wide, 30km deep buffer zone in northern Syria, Turkey and the Syrian National Army's (SNA) first targets were the border towns of Tal Abyad and Ras al-Ain, held by the Kurdish-dominated Syrian Democratic Forces (SDF).

Having achieved these goals, their next targets will be SDF areas deeper inside Syria, including Manbij and Tal Rifaat, members of the Syrian National Army, told °®Âþµº this week.

The regime also have their eyes on these two towns, with a race for control of territories in northern Syria breaking out with the apparent collapse of the SDF, after the US cut support for its one-time ally, after the defeat of the Islamic State group (IS).

Operation Peace Spring's chied aim at clearing the Syrian border area of the SDF's Kurdish People's Protection Units (YPG), which Turkey links to the banned Kurdistan Workers' Party (PKK).

Ankara says the operation will allow it to create a "safe zone" inside Syria to resettle around 1 million of the country's 3.6 million Syrian refugees and ensure that IS does not re-emerge, but many are sceptical about Turkey's plan.

Fighting has already led to mass displacement in northern Syria, with at least 130,000 civilians uprooted so far and as many as 450,000 expected to flee their homes during the campaign, according to some aid groups.

At least 38 Syrian civilians were killed during the first four days of the campaign, while another eight people lost their lives after suspected Kurdish militia shelling of Turkish border towns.

Fighting between the two sides has also cost many lives with Ankara claiming to have killed 480 members of the YPG - the dominant militia in the SDF - so far, although the Syrian Observatory for Human Rights puts the figure at 81.

At least 49 SNA fighters and one Turkish soldier have also been killed in clashes that have erupted across wide stretches of the Turkey-Syria border.

Although it is mostly Arab-majority areas that have been affected by the campaign so far, shelling and bombing has forced tens of thousands of civilians to flee their homes.

Aid groups and analysts are warning that the worst is yet to come as fighting potentially moves into most densely-packed towns. If the regime intervenes in Raqqa province, then the number who will flee the other way could also be in the thousands.

"Tal Abyad and Ras al-Ain have been very heavily bombed but the other areas not so much," said Elizabeth Tsurkov, Fellow at the Foreign Policy Institute, who has been speaking to people in areas affected by the military campaign. 

"There have been quite a lot of shelling of Qamishlo (Qamishli) which is very concerning because it is the most densely populated city in all SDF areas."

Read also: Turkey's plan to capture northern Syria from Kurdish forces

Turkish-backed Syrian rebels have so far captured the border towns of Tal Abyad and Ras al-Ain, according to Ankara, with the force moving deeper into SDF territories towards Ain Al-Issa. 

"Some Arabs who have relatives in the Turkish-backed factions want their sons to return and they really don't like the SDF, particularly in Tal Abyad, which is an Arab-majority town with a small Kurdish population that has been empowered, which has created some tensions," Tsurkov said.

"The overwhelming desire for people in all SDF areas is stability, so even if you don't like the current situation then the prospect of invasion is a major concern for a lot of people."

The previous Turkish-Syrian rebel offensive on Afrin, in northwest Syria, resulted in looting by some pro-Ankara fighters, but Erdogan has reportedly warned the force against such behaviour during this campaign. 

Guarding IS prisons is no longer a priority. Whoever cares about the secure detention of the prisoners, they are welcome to come and find a solution.

Commanders have been told to "continuously supervise combatants on the frontlines to prevent any abuse", The Guardian had reported, and those found guilty "would face the most severe sanctions and be brought to justice for military disobedience".

Despite this, nine civilians were reportedly "executed" on Saturday by pro-Ankara fighters on the M4 highway in northern Syria including Hevrin Khalaf, secretary-general of the Future Syria Party.

Circumstances around her death are still unclear with various reports suggesting she was killed in an ambush on her vehicle, shot dead at a checkpoint, or targeted in airstrikes. 

— Thomas van Linge (@ThomasVLinge) " style="color:#fff;" class="twitter-post-link" target="_blank">Twitter Post BREAKING: regime forces are set to enter and as the is forced to withdraw from the area between Tall Abyad and Serekaniye. and are the winners of today — Thomas van Linge (@ThomasVLinge)

The Syrian National Army has denied they were behind the killing, although mobile phone video footage shared on social media allegedly shows the summary execution of civilians by Turkish-backed fighters in the M4 area.

IS insurgency 

Amid the fighting, numerous other actors will be looking to take advantage of the turmoil. The Syrian regime has rejected working with the SDF but said it would fight the "Turkish invasion", suggesting that its forces might move into the Kurdish-held areas, including Manbij and Tal Rifaat - possibly Raqqa and other Arab Sunni-majority towns and villages.

Tsurkov believes that Russia, Turkey, and the Syrian regime will be the principal beneficiaries from the campaign if the SDF collapse, which appears more likely as each day in the campaign progresses.

"Russia is the main player who will gain most out of this. It is able to both satisfy some Turkish desires, as it has done previously in Afrin, and also if the SDF collapses it will be forced to negotiate with the regime and handover territory to it. So it tends to gain from whatever scenario unfolds," Tsurkov told °®Âþµº.

"The regime is also going to gain from this because if the SDF realise the Americans are not going to provide it with backing then they will be forced to capitulate to the regime."

The Islamic State group is perhaps the biggest concern for many, with northeastern Syria said to be ripe for insurgency, particularly if the Turkish-backed and SDF are too busy battling each other, to police the region. 

US President Donald Trump's decision to withdraw American troops from regions of fighting has seen him face widespread criticism. This is not just because Trump's announcement of the withdrawal last Sunday appeared to give Ankara a green light to launch the offensive, but also because the situation will likely benefit IS, which has been waiting in the shadows.

This insurgency could arise not just from IS sleeper cells, but also in the seven major camps and prisons holding 12,000 suspected IS fighters, while tens of thousands of family members who are also being detained in under-guarded camps.

The SDF has reportedly cut the number of guards at the largest of these, Al-Hol, to 300 due to the offensive. Al-Hol houses 60,000 people - mostly women and children - and there have been attempts by IS supporters to take control of the camp prior, and following, the offensive.

If the SDF collapses it will be forced to negotiate with the regime and handover territory to it.

The Kurdish factions have said their fighters will concentrate on fighting the Turkish offensive, putting security at these camps at risk as guards head for the front-lines.

There have been a number of attempted and successful break-outs by detainees since Operation Peace Spring began.

"Guarding IS prisons is no longer a priority. Whoever cares about the secure detention of the prisoners, they are welcome to come and find a solution," said Kurdish official Redur Xelil.

This culminated in Kurdish authorities on Sunday claiming that 785 foreigners affiliated with IS escaped one camp following Turkish shelling in the area. 

An audio recording of IS leader Abu Bakr Al-Baghdadi last month urged supporters to storm the camps and launch attacks inside Syria.

Fighting between the SDF and Turkish backed forces - who both defeated the group in northern Syria in seperate offensives - could provide IS with this opportunity.

"The deeper the Turkish force goes into Syria, the more IS will be able to take advantage of the situation of general instability and shelling around prisons," Tsurkov said.

Europe is alarmed by this potential threat arising from IS during the offensive, with Germany, France, Norway among others to freeze arms exports to Turkey in retaliation for Operation Peace Spring.

Tsurkov said that although the SDF have used fears among the international community of IS as a pressure card, the fighters will be extremely concerned by a the prospect of an insurgency.

Syrian civilians in the east are deeply fearful that this scenario will soon become reality, particularly if more breakouts from camps of militants and supporters take place.

"If IS prisoners are able to escape the first target will be the SDF, long before they manage to reach Europe. They will be able to kill SDF fighters or civilians, so they have supreme interest in maintaining control of the IS prison population."

With the offensive, northern Syria could become contested by Turkey, IS, SDF, Russia and the Syrian regime once again. 

Having abandoned its one-time ally - the SDF - with orders for the complete withdrawal of American troops, then then the future for Syria is far from certain.

Paul McLoughlin is a news editor at °®Âþµº. 

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