In this April 4, 2018 file photo, a U.S-backed Syrian Manbij Military Council soldier passes a U.S. position near the tense front line with Turkish-backed fighters, in Manbij, north Syria. Image Credit: AP

Occupied Jerusalem: The United States decision to withdraw from Syria has abruptly scrambled the geopolitics of the Middle East, clearing the way for Iran to expand its influence across the region, leaving Israel virtually alone to stop it, and raising the prospect that thousands of Daesh prisoners could be set free.

Beyond the region, President Donald Trump’s announcement ricocheted Thursday from Moscow, where it was praised, to Washington, where it was the catalyst for the resignation of Defense Secretary Jim Mattis.

The decision shows that even a relatively small move - the United States has only about 2,000 troops in Syria - can have far-reaching consequences in a complex war, leaving allies struggling to cope and adversaries pleased and emboldened.

“Donald’s right, and I agree with him,” said President Vladimir Putin of Russia, whose influence over Syria can only grow more dominant as the United States exits.

Turkey, Iran and the Syrian government of President Bashar Al Assad also stand to reap enormous immediate benefits from the US withdrawal.

On the other hand, allies like the Kurdish forces who fought alongside the United States in Syria feel betrayed and are threatening to free thousands of Daesh prisoners if the United States abandons them.

As the US decision ripples across the region, many countries will be forced to reassess their relationships.

Bulwark against Iran

The US presence in Syria was particularly vexing for Iran, preventing Iranian-backed militias from crossing into Syria from Iraq.

A pullout would free Tehran to treat the Iraqi border as fully porous, easing the movement of fighters and weapons - and potentially of the advanced missiles and other weapons through Syria to Hezbollah, Iran’s partner in Lebanon.

upporters of Lebanon's Hezbollah leader Sayyed Hassan Nasrallah gesture as they hold Hezbollah flags in Marjayoun, Lebanon May 7, 2018. Image Credit: Reuters

That freedom of movement could also ease the pain of US sanctions, which are damaging Iran’s economy. “The area is oil-rich,” said Lina Khatib, a Middle East expert at Chatham House in London. “So removing US troops could increase the chances of Iran getting its hands on oil fields in the northeast.”

Kurds stand to lose

No constituency stands to lose more from a United States withdrawal than its Kurdish allies in eastern Syria.

As if to signal that it would not go quietly, the Kurdish-led Syrian Democratic Forces are discussing the release of 3,200 Daesh prisoners, a prominent monitoring group and a Western official said Thursday.

Mostapha Bali, the spokesman for the Syrian Democratic Forces, denied there was any discussion of releasing prisoners from the Daesh.

A member of the Syrian Democratic Forces (SDF) holding his rifle in Hajin, in the Deir Ezzor province, eastern Syria, on December 15, 2018. Image Credit: AFP

“Any news coming from such sources is not reliable and is not coming from us,” he said.

But a Western official from the US-led coalition fighting in Syria, which includes more than a dozen countries, confirmed that such discussions had taken place.

“The best result of terrible options is probably for the Syrian regime to take custody of these people,” said the official, who insisted on anonymity because he was not permitted to speak publicly.

“If they are released, it’s a real disaster and major threat to Europe.”

Some analysts played down the threat as a bluff, or a cry for attention, saying that if the Daesh prisoners were freed, they could sooner be expected to turn on the Kurds than thank them.

But a report by the Syrian Observatory on Human Rights said the Syrian Democratic Forces leadership was discussing the prisoners’ release because many of their home countries had refused to take them back.

Turkish green light

The Observatory, a London-based group with a network of citizen monitors throughout Syria whose work is widely considered credible, said the militia was also concerned that it would need all its fighters to defend against a possible Turkish military invasion.

That invasion became more likely with Trump’s announcement, which was seen as giving Turkey a green light to carry it out.

The US withdrawal helps Turkey in two ways: it abandons the Kurds, whom Turkey sees as a threat, and removes US troops from northeastern Syria, which President Recep Tayyip Erdogan said he will invade to attack Kurdish positions there.

An invasion, however, would not be free of risk.

People are pictured walking in the Syrian town of Darbasiyah on December 13, 2018 as the Turkish flag flutters on the opposite side of the border crossing with Turkey. Image Credit: AFP

“The problem for them is that if they do go in, there is always the possibility that they run into a protracted guerrilla struggle,” said Steven A. Cook, a Middle East expert at the Council on Foreign Relations.

The greater likelihood, analysts said, was that the Kurds seek an agreement with Syria’s president, Al Assad, that grants them limited autonomy in eastern Syria in exchange for their loyalty.

Such an agreement would put Turkey into greater conflict with Al Assad and the Russians.

Russia biggest beneficiary

Russia may be the biggest beneficiary of a US departure, which would leave it as the major global power in Syria and restore its Soviet-era role as a player in the Middle East.

Putin’s praise for Trump aside, he is likely to use a US withdrawal to “tell the world that Russia’s won against the US in this proxy war,” said Khatib of Chatham House.

Vladimir Putin, Russia's president, speaks during his annual news conference in Moscow, Russia, on Thursday, Dec. 20, 2018. Image Credit: Reuters

And with good reason, she added: “Russia will take advantage of the vacuum to set the terms for the trajectory of the Syrian conflict as it wishes. It paves the way for Russia to treat Syria as part of its virtual territory.”

But while Moscow and Tehran may both gain in the short term, the end of the war in Syria is likely to bring them into conflict, as their alliance in support of Al

Assad will give way to competing interests: Russia wants a strong government in Damascus that is loyal to Moscow, while Tehran wants a weak regime on which it can impose its will.

“It seems to me we’re seeing the rise of a new axis in the Middle East, aligning Russia, Israel and countries like Saudi Arabia against Iran,” Khatib said. “But this will take a while to play out. And it does not remove the immediate danger that is now going to increase when it comes to Israel’s own security.”