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Two weeks ago, all US troops were poised to leave Syria, as Turkish forces launched a full-scale assault on Kurdish-controlled areas in the north of the country.

With another humanitarian crisis unleashed in Syria and President Donald Trump facing widespread criticism for his ill-thought out withdrawal plan, it was said that some 300 American troops would remain at the southern base of Al-Tanf.

Fears of a new Islamic State [IS] group insurgency in eastern Syria has seen Washington hint that hundreds more American soldiers could be deployed to guard gas and oil fields in Deir az-Zour, adding to the confusion about the planned US withdrawal from Syria.

Oil fields

American tanks and heavy weaponry would be part of the residual force in eastern Syria, according to the media, marking another surprise twist since Trump announced an end to the US military presence in the country, two weeks ago.

American firepower in Deir az-Zour could offset the threat posed by IS to takeover oil fields, following an uptick in bombings of areas controlled by Washinton's former allies, the Syrian Democratic Forces (SDF).

The move could also sidestep alleged Syrian regime plans to retake resource-rich areas of Deir az-Zour, something that would provide Damascus with much-needed revenue sources and also extend the dominance of Iranian militias in the Syria-Iraq border.

Haian Dukhan, a UK-based Syrian academic and author of State and Tribes in Syria, said that an American deployment to eastern Syria would be motivated by these strategic factors.

"[Some in the] US administration have said that sanctions on the Syrian regime will be seriously weakened if [Damascus] takes the oil fields, and so the US will try to get a hold of them," Dukhan told °®Âþµº.

The plans of the US residual force, hints that Washington could be thinking again about the power vacuum that could arise from a full-scale American withdrawal from Syria – one that would benefit its foes, chiefly IS and Bashar al-Assad.

Turkey's offensive on SDF territories two weeks ago, has upturned relative stability in some parts of Deir az-Zour and Raqqa as Kurdish forces were rushed to the frontlines in northern border regions rather than policing eastern Syria.

Security at so-called "IS prisons" in eastern Syria – holding militants, their families, and other civilians – appears to be failing with the guard force massively depleted and reports of detainees increasingly taking the law into their own hands.

Deir az-Zour, a former stronghold of IS, would likely be the location of a new insurgency by the group, Dukhan said, and the region's oil and gas fields once provided the extremists with a valuable source of income.

"Jabhat al-Nusra was formed here, many of the tribes from Deir az-Zour joined IS and the fact that it has social, geographical extensions into Iraq makes it one of the major battlefields against IS in the future," said Dukhan.

Regime takeover

Although defeated, IS sleeper cells are still thought to be operating in Deir az-Zour, making it likely that SDF forces and civilians could be the prime targets in a new insurgency.

Dukhan notes that a small IS enclave near Palmyra, in central Syria, has seen fighters take advantage of the region's warren of caves and weak regime military presence to launch frequent attacks on military checkpoints and locals.

The instability means that much of the population of the Palmyra region have refused to return, wary of being targeted by IS or the regime militias, something that could play out in other parts of eastern Syria if the group could make a foothold.

"If the US really wants to have some sort of leverage in eastern Syria, then having a base there would work to counterbalance Iran's presence in the region [and IS]," Dukhan said.

"There are many people in the US administration that view pulling out of Syria as enabling an [IS] resurgence and would also strengthen Iran in Syria."

He said that if an American presence were maintained in eastern Syria it would allow for sanctions on the regime to continue, prevent Iran from extending its presence in Deir az-Zour and provide Washington with a ground force to monitor the passage of IS fighters between Iraq and Syria.

"If the Americans pull out and the regime move in, then there will likely be a power vacuum. The regime do not have enough troops and sleeper cells would likely launch attacks… IS fighters on both sides of the Euphrates River could use this as an opportunity to reconnect," he added.

One of the locations in Deir az-Zour likely to be reinforced by the regime is the Conoco gas plant, according to the Guardian.

The industrial plant witnessed the most significant clash during the war between the regime and SDF, when hundreds of Russian mercenaries and regime militia fighters were killed in US shelling and airstrikes, as they attempted to storm the complex.

Having being seriously weakened after eight years of gruelling fighting, the Syrian regime has neither the manpower, or willpower, to takeover and directly rule the country's east.

This is despite the repeated threats by Assad to take the war to the SDF, who he has referred to as an "American proxy".

The strong opposition presence in Idlib and a growing insurgency in Daraa province will likely be enough to keep Damascus busy for now, but that does not mean Assad won't try to strike deals with the SDF's dominant Kurdish faction – the People's Protection Units (YPG) – to see eastern Syria, officially, come under state control, Dukhan said.

Read also: Syria's north is up for grabs as Turkey offensive begins

As was witnessed in Kobane and Manbij, the YPG clearly prefer this option rather than to surrender their territories in Turkey, where Kurdish and regime militias operate in parallel, with a general quiet for now.

"The SDF is still effectively in control of these towns and the regime presence is symbolic, so things haven't changed much. I don't think there as been friction at the moment," Dukhan said.

Alliance

Even if the US does bolster its military presence in resource-rich areas of Deir az-Zour, it will be unlikely to remain in Syria for the long-term.

Russia would likely move in, the academic added, providing the SDF with an option of amnesty in return for coming under the authority of the regime.

This could see YPG militias being incorporated into the Russian-led Fifth Corps, an army division which has already integrated former rebel groups in southern Syria and the Kurdish fighters, with their expertise in fighting IS and knowledge of eastern Syria would be welcome recruits.

"I think the advice of the Russian military advisers to the regime will be that [with the SDF] you already have a force that fought against IS for many years, has a lot of intelligence information, has been patrolling the vast desert areas to the east of the Euphrates River, and so why would you want to open a new military front against them," said Dukhan.

"Better to try to include these fighters into [regime] militias, like the Fifth Corps under Russian command. They could take advantage of their expertise, knowledge of the area and communities, but on the condition of the SDF accepting the return of the Syrian state."

Dukhan noted that another asset for the Assad regime in eastern Syria would be the camps holding IS detainees and families.

Western counties are well aware of the erratic nature of the regime, which includes cooperating with extremist groups during the Iraq war and trading with IS during the current one.

There are now fears that European nationals, linked to IS, who are held in these camps could be used as "pawns" by the Syrian regime with the West and that threats to empty the camps could see concessions being secured from Europe.

"It seems that we are heading to a stage where these camps will eventually come under the control of the regime, slash SDF… these will give the regime a bargaining chip with the west," Dukhan added.

"We have a history of the regime using these jihadists after the 2003 [US-led invasion of Iraq] and at the beginning of the Syria civil war, releasing them from jails for political reasons. It is concerning that the Syrian regime will have control of these camps and detention centres, we don't know what the regime will do with them."

Paul McLoughlin is a news editor at °®Âþµº. 

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