US President Donald Trump‘s decision to withdraw troops from northeast Syria before a Turkish military campaign was slammed by Democrats, as well as some of his strongest Republican defenders on Monday.

“The president’s decision to withdraw US forces from northern Syria is a deeply disturbing development that betrays our Kurdish allies who have been instrumental partners in our mission to eradicate ISIS,” House Speaker Nancy Pelosi said, referring to the Islamic State of Iraq and the Levant (ISIL or ISIS).

“Despite what the president might say, ISIS remains a serious threat. This reckless, misguided decision undermines the efforts by our brave service members and our allies to end ISIS’s tyranny,” the top Democrat in the House of Representatives added.

White House Press Secretary Stephanie Grisham said in a statement on Sunday that “Turkey will soon be moving forward with its long-planned operation into northern Syria”, and US forces “will not support or be involved in the operation” and “will no longer be in the immediate area”.

The US withdrawal marks a major shift in US policy and effectively abandons Kurdish fighters in the battle against ISIL, which took over swaths of Syria before being defeated a year ago.

The Kurdish-led Syrian Democratic Forces (SDF) warned that a Turkish invasion will overturn the victory over ISIL. An SDF spokesman said the group viewed Trump’s decision as a “stab in the back“.

Senator Lindsey Graham, who has in recent years become one of Trump’s strongest supporters, led the litany of rebukes from Republicans, vowing to call on Congress to reverse the sudden decision.

“This is a disaster in the making,” Graham tweeted.

Graham also announced he and Senator Chris Van Hollen, a Democrat, will introduce legislation calling for sanctions against Ankara if Turkey invades Syria, and “will call for their suspension from NATO if they attack Kurdish forces who assisted the US in the destruction of the ISIS Caliphate”.

Hope and expect sanctions against Turkey – if necessary – would be veto-proof. This decision to abandon our Kurdish allies and turn Syria over to Russia, Iran, & Turkey will put every radical Islamist on steroids. Shot in the arm to the bad guys. Devastating for the good guys. — Lindsey Graham (@LindseyGrahamSC) October 7, 2019

Graham’s sentiments were echoed by Senate Majority Leader Mitch McConnell, who said “a precipitous withdrawal of US forces from Syria would only benefit Russia, Iran, and the Assad regime. And it would increase the risk that ISIS and other terrorist groups regroup.”

Republican Congresswoman Liz Cheney wrote, “Withdrawing US forces from Northern Syria is a catastrophic mistake that puts our gains against ISIS at risk and threatens US security”.

Withdrawing US forces from Northern Syria is a catastrophic mistake that puts our gains against ISIS at risk and threatens US security. This decision ignores lesson of 9/11. Terrorists thousands of miles away can and will use their safe-havens to launch attacks against America. — Liz Cheney (@Liz_Cheney) October 7, 2019

Meanwhile, Republican Senator Mitt Romney called the withdrawal “a betrayal” that facilitates ISIL’s come back.

Turkish President Recep Tayyip Erdogan said on Saturday a military incursion into northeast Syria was imminent, after Ankara accused Washington of stalling efforts to establish a “safe zone” there together.

Despite starting patrols in September, the US and Turkey have disagreed over several important details of the zone, including the fate of the Kurdish troops currently operating there.

Turkey wants to rid the region of the Kurdish People’s Protection Units (YPG) armed group. Ankara considers the YPG to be an extension of the Kurdistan Workers’ Party (PKK) which has waged a decades-long armed campaign for autonomy in Turkey.

Ankara and Washington consider the PKK a “terrorist” group but they diverge on the issue of the YPG, which forms the core of US-backed Syrian forces against ISIL.

Leaving US allies ‘to die’

Trump, who announced the withdrawal and that the Turkish military campaign will go forward after a phone call with Erdogan, took to Twitter to defend the move, saying the region would have to “figure the situation out”.

“The Kurds fought with us, but were paid massive amounts of money and equipment to do so,” he said.

“They have been fighting Turkey for decades. I held off this fight for almost 3 years but it is time for us to get out of these ridiculous Endless Wars, many of them tribal, and bring our soldiers home.”

Following the volley of criticism on Monday, Trump tweeted he would totally “destroy and obliterate the economy of Turkey” if Ankara does anything he considers “off-limits”.

As I have stated strongly before, and just to reiterate, if Turkey does anything that I, in my great and unmatched wisdom, consider to be off limits, I will totally destroy and obliterate the Economy of Turkey (I’ve done before!). They must, with Europe and others, watch over… — Donald J. Trump (@realDonaldTrump) October 7, 2019

He continued his defence later on Monday, telling reporters he was not siding with anyone on his decision to withdraw US troops from the area. He also said he campaigned on an agenda of bringing US troops home.

Nevertheless, the push-back continued, with Trump’s former United Nations envoy Nikki Haley tweeting the US troop withdrawal was leaving US allies “to die”.

“We must always have the backs of our allies, if we expect them to have our back,” said Haley, a Republican. She added the Kurds were “instrumental” in the US fight against ISIL.

Several 2020 Democratic hopefuls also condemned the decision. Senator Bernie Sanders tweeted that while he supports ending US military intervention in the Middle East, Trump’s “extremely irresponsible” announcement is “likely to result in more suffering and instability”.

Senator Elizabeth Warren, who is also vying for the Democratic ticket, said the withdrawal “undermines both our partners and our security”.

“We need a strategy to end this conflict, not a president who can be swayed by one phone call,” she said in a tweet.

Former Secretary of State Hillary Clinton, who Trump defeated in the 2016 election, also took to Twitter to accuse the president of committing “a sickening betrayal both of the Kurds and his oath of office”.