WASHINGTON (BLOOMBERG) - United States President Donald Trump's decision to pull troops out of Syria came under renewed pressure after a suicide attack claimed by Islamic State in Iraq and Syria (ISIS), the terrorist group the President said a month ago was effectively defeated.
Four Americans were killed and three wounded in the attack in the northern town of Manbij on Wednesday (Jan 16). The Pentagon said its forces were on a "routine patrol" when the attack occurred.
The incident represents the latest hurdle to Mr Trump's goal of bringing US troops home from intractable Middle East conflicts, an issue he campaigned on two years ago but has made little progress in carrying out.
Since abruptly announcing he was bringing troops home from Syria "now", Mr Trump and his top advisers have sought to establish specific conditions for the withdrawal: promising to depart slowly, to continue striking ISIS on the way out and seeking assurances from Turkey that it wouldn't attack America's Kurdish allies.
But Republican Senator Lindsey Graham of South Carolina, a prominent Trump ally who's critical of his Syria plan, quickly seized on the deadly incident to urge that the President reconsider his decision to pull out the roughly 2,000 American troops, saying his announcement backfired by encouraging ISIS to strike.
Mr Trump's statements "set in motion enthusiasm by the enemy we're fighting" and "make people we're trying to help wonder about us, and as they get bolder, the people we're trying to help are going to get more uncertain", Mr Graham said at a Judiciary Committee hearing.
'Stay the Course'
Mr Trump's defenders were equally quick. Republican Senator Rand Paul of Kentucky suggested the suicide strike showed the futility of keeping US forces in the country after much of ISIS's territorial footprint had been eliminated.
"If you're going to wait for a time when perfect peace breaks out in the Middle East, you'll never leave," Mr Paul said in an interview, adding that he planned to go directly to Mr Trump to say "stay the course".
Turkish President Recep Tayyip Erdogan, who has long sought a US departure so he could target the Kurdish militias he calls terrorists, said any hesitation by Mr Trump in withdrawing would "amount to a victory" for ISIS.
The day's events renewed a tug-of-war over a policy that has divided the administration. The President's original announcement led to the resignation of Defence Secretary James Mattis and the top US envoy to the global coalition to defeat ISIS.
In addition to fuelling concern that the US was abandoning its Kurdish allies on the battlefield, it sparked speculation that the withdrawal would give ISIS space to regroup. A 2018 report by the Pentagon's inspector general said the group still had as many as 30,000 fighters in Syria and neighbouring Iraq.
"Those favouring withdrawal will say that these deaths are the sort of pointlessly incurred costs that should be ended by getting US troops out of Syria," said Professor Paul Pillar of Georgetown University, who is a former CIA officer.
"Those resisting withdrawal will argue that the bombing demonstrates that ISIS has not been defeated. The latter position is more likely to have impact on policy."
Islamic State's self-styled Amaq news agency said a suicide bomber wearing an explosive vest attacked international forces in Manbij. The Syrian Observatory for Human Rights, which monitors the almost eight-year-old civil war through activists on the ground, says the blast killed at least 16 people.
"Although it is unclear at this point whether US personnel were specifically targeted in today's bombing, it is interesting to speculate on ISIS strategy in the event that they were," Prof Pillar said.
"Rather than waiting out the Americans until US troops have withdrawn, ISIS may see advantage in having some of those troops remain - and possibly ISIS intended the attack to strengthen the 'withdrawal would be premature' argument in the United States."
After Mr Trump initially declared the group defeated in December, he later qualified the claim to say Islamic State had lost territorial control of the self-proclaimed caliphate it once held.
The US and its allies have weakened the group and captured hundreds of their fighters who face an uncertain future in the hands of Kurdish forces.
The suicide bombing will undermine Mr Trump's arguments that America's job in Syria is finished, according to Mr Philip H. Gordon, a senior fellow at the Council on Foreign Relations and former president Barack Obama's coordinator for the Middle East, North Africa and the Gulf Region from 2013-2015.
"This attack undermines the basis on which he declared a withdrawal advisable," Mr Gordon said. "You can still have a good, legitimate debate about how long we should stay in Syria. What you can't do is claim that we can now leave because ISIS has been defeated."
'In the Pipeline'
The confusion has also stoked tensions with Nato ally Turkey. The town of Manbij, where ISIS struck, is at the heart of the dispute over US support for the Kurdish fighters.
Whether the Americans were directly targeted or accidental victims is irrelevant to the political debate now, according to Mr Kamran Bokhari, a foreign policy specialist at the University of Ottawa's Professional Development Institute.
"This attack was likely in the pipeline even if the President had not announced the decision to pull out forces," Mr Bokhari said. "That said, perception matters more than reality, and this makes the administration look really bad and greatly empowers his opponents."
Vice-President Mike Pence suggested the attack won't derail Mr Trump's plans - as modified to allow for a cautious pace of withdrawal.
"We have crushed the ISIS caliphate and devastated its capabilities," Mr Pence said in statement on Wednesday.
"As we begin to bring our troops home, the American people can be assured, for the sake of our soldiers, their families, and our nation, we will never allow the remnants of ISIS to re-establish their evil and murderous caliphate - not now, not ever."