Washington - President Donald Trump has begun what will be a total withdrawal of U.S. troops from Syria, declaring on Wednesday they have succeeded in their mission to defeat Daesh and were no longer needed in the country.
A decision to pull out completely, confirmed by U.S. officials and expected in the coming months, coincides with the roughly 2,000 U.S. troops finishing up a campaign to retake territory once held by Islamic State militants.
But it could leave the United States with few options to prevent a resurgence of Daesh. It could also undercut U.S. leverage in the region and undermine diplomatic efforts to end the Syrian civil war, which is now in its eighth year.
"They're all coming back and they're coming back now. We won," Trump declared on Wednesday in a video posted on Twitter.
News of a full withdrawal drew immediate criticism from some of Trump's fellow Republicans, who said that leaving strengthened the hand of Russia and Iran, which both support Syrian President Bashar al Assad.
It may also leave exposed an alliance of Kurdish and Arab militias known as the Syrian Democratic Forces, or SDF, which has been among the most effective against Daesh but is under threat as Turkey weighs a new offensive in Syria.
U.S. commanders on the ground, who have developed strong ties to SDF leaders, had voiced concerns about what a fast withdrawal would mean for the U.S-backed forces and were surprised by the decision, U.S. officials told Reuters, speaking on condition of anonymity.
But Trump said that he considered the mission in Syria over given Daesh territorial losses.
Trump's predecessor, Barack Obama, was slow to get involved in Syria's civil war, fearing being dragged into another open-ended foreign conflict like the one in Afghanistan.
Hundreds of thousands of people have been killed in the conflict, which has displaced around half of Syria's pre-war 22 million population.
But in a campaign to defeat Daesh in Syria, Obama ordered air strikes from September 2014 and then troops into the country the following year.
The White House declined to offer a timeline for withdrawal.
One U.S. official said Washington aimed to withdraw troops within 60 to 100 days and said the U.S. State Department was evacuating all its personnel in Syria within 24 hours.
A second official said they could leave even sooner.
Turkey: Syrian Kurdish militants to be buried
Many of the remaining U.S. troops in Syria are special operations forces working closely with the SDF.
The partnership with the SDF has helped defeat of Daesh in Syria but has outraged NATO ally Turkey, which views Kurdish YPG forces in the alliance as an extension of a separatist militant group fighting inside Turkey.
Ankara is threatening a new offensive in Syria. To date, U.S. forces in Syria have been seen as a stabilizing factor and have somewhat restrained Turkey's actions against the SDF.
Turkey said Kurdish militants east of the Euphrates in Syria "will be buried in their ditches when the time comes", after President Donald Trump began what will be a total withdrawal of U.S. troops from Syria.
The two countries have long had their relations strained by differences over Syria, where the United States has backed the Syrian Kurdish YPG in the fight against Daesh. Turkey considers the YPG a terrorist group and an extension of the outlawed Kurdistan Workers Party (PKK).
"Now we have Manbij and the east of the Euphrates in front of us. We are working intensively on this subject," state-owned Anadolu news agency on Thursday reported Defence Minister Hulusi Akar as saying during a visit to a Qatari-Turkish joint military base in Doha.
"Right now it is being said that some ditches, tunnels were dug in Manbij and to the east of the Euphrates. They can dig tunnels or ditches if they want, they can go underground if they want, when the time and place comes they will buried in the ditches they dug. No one should doubt this." It was not clear when Akar was speaking.
President Tayyip Erdogan said this week that Turkey may start a new military operation in Syria at any moment, touting support from Trump even though the Pentagon had issued a stern warning to Ankara.
The Pentagon had said that unilateral military action by any party in northeast Syria, where U.S. forces operate, would be unacceptable.
Turkey has already intervened to sweep YPG and Islamic State fighters from territory west of the Euphrates over the past two years. It has not gone east of the river, partly to avoid direct confrontation with U.S. forces.
Trump is wary of open-ended foreign conflicts and his decision on Syria raises questions about whether he may also reconsider the U.S. war effort in Afghanistan, where American forces have been fighting since 2001.
Trump reluctantly agreed to a troop increase last year but U.S. officials have privately acknowledged a sense of urgency and are increasingly focused on securing a peace deal with a resurgent Taliban.
Some of Trump's Republican allies in Congress railed against the pullout decision. U.S. Senator Lindsey Graham, often a Trump ally but generally a foreign policy hawk, said a withdrawal would have "devastating consequences" for the United States in the region and throughout the world.
"An American withdrawal at this time would be a big win for ISIS, Iran, Bashar al Assad of Syria, and Russia," Graham said in a statement.
The surprise decision also raised eyebrows abroad.
A British defense minister said he strongly disagreed with Trump that Daesh had been defeated in Syria. Israeli Prime Minister Benjamin Netanyahu said Israel would study the decision and would ensure its own security.
France’s defense minister said on Thursday that Daesh militants had been weakened but not been wiped from the map in Syria and that the fight to defeat them definitively in their remaining pockets needed to carry on.
“Islamic State has been weakened more than ever,” Florence Parly said on Twitter, responding to U.S. President Donald Trump’s announcement on Wednesday that the group had been defeated.
“But Islamic State has not been wiped from the map nor has its roots. It is necessary that the last pockets of this terrorist organization be definitively defeated militarily.”
In Russia, TASS news agency quoted the Foreign Ministry as saying withdrawing U.S. troops from Syria created prospects for a political settlement.
A complete withdrawal of U.S. troops from Syria would leave a sizeable U.S. military presence in the region, including about 5,200 troops across the border in Iraq. Much of the U.S. campaign in Syria has been waged by warplanes flying out of Qatar and other locations in the Middle East.
Still, Defense Secretary Jim Mattis and State Department officials have long fretted about leaving Syria before a peace agreement can be reached.
Daesh is also widely expected to revert to guerilla tactics once it no longer holds territory. The United States has not ruled out Daesh leader Abu Bakr Al Baghdadi could still be alive.
A U.S. withdrawal could open Trump up to criticism if Daesh reemerged.
Trump had lambasted Obama for the withdrawal of U.S. forces from Iraq that preceded an unraveling of the Iraqi armed forces.
Iraqi forces collapsed in the face of Daesh's advance into Iraq in 2014.
A senior administration official rejected the comparison to Iraq, where the United States had many more troops and would have stayed if Baghdad had provided legal protections for the American forces.
"That's an apples and oranges comparison given the scope and scale of our engagement in Iraq," the official said.
Daesh declared its so-called "caliphate" in 2014 after seizing large swathes of Syria and Iraq. The hardline group established its de facto capital in the Syrian city of Raqqa, using it as a base to plot attacks in Europe.
According to U.S. estimates, the group oversaw about 100,000 square kilometers of territory, with about 8 million people under Islamic State control. It had estimated revenues of nearly one billion dollars a year.
A senior U.S. official last week said the group was down to its last 1 percent of the territory it once held. It has no remaining territory in Iraq.
Hajin, the group's last major stronghold in Syria, is close to being seized by U.S.-backed SDF forces.
After losing Hajin, Daesh will control a diminishing strip of territory along the eastern bank of the Euphrates River in the area where U.S.-backed operations are focused. Militants also control some desert terrain west of the river in territory otherwise controlled by the Damascus government and its allies.
U.S. officials have warned that taking back the group's territory would not be the same as defeating it.
"The Coalition has liberated the ISIS-held territory, but the campaign against ISIS is not over," Pentagon spokeswoman Dana White said in a statement.