Just two days after US Secretary of Defense James Mattis quit, the top US envoy leading the global coalition fighting ISIS, Brett McGurk, also resigned as Washington reeled from US President Donald Trump’s dramatic announcement that he planned to pull US troops out of Syria.According to media reports, McGurk, in his resignation letter to Secretary of State Mike Pompeo, said that the militants were still on the run but not yet defeated, and that the early withdrawal of American troops from Syria would re-create the conditions that gave rise to ISIS. News of McGurk’s resignation was published on Saturday and is expected to go into effect on December 31.Earlier this month, on December 11th, McGurk spoke of the importance of US troops remaining in Syria.“It would be reckless if we were just to say, well, the physical caliphate is defeated, so we can just leave now,” he said. “Even as the end of the physical caliphate is clearly now coming into sight, the end of ISIS will be a much more long-term initiative.”Mattis did not mention Syria specifically in his resignation letter published late on Thursday, but he did speak of a difference of opinion between himself and Trump.“You have the right to have a Secretary of Defense whose views are better aligned with yours on these and other subjects,” Mattis wrote.“I believe it is right for me to step down from my position. The end date for my tenure is February 28, 2019, a date that should allow sufficient time for a successor to be nominated and confirmed,” he added.In the aftermath of his resignation, Mattis canceled a visit to Israel set for this week, an official confirmed for The Jerusalem Post.Trump on Saturday continued with his slew of tweets defending the Syria announcement.“We were originally going to be there for three months, and that was seven years ago – we never left. When I became President, ISIS was going wild. Now ISIS is largely defeated and other local countries, including Turkey, should be able to easily take care of whatever remains. We’re coming home!” Trump wrote.Prime Minister Benjamin Netanyahu has taken pains to make statements reassuring Israelis that their security has not been compromised. He also pledged to increase Israeli activity against Iran in Syria.Ministers and politicians from parties who belong to the government coalition have been loath to criticize the US over the decision, which will likely weaken US influence in the region.The absence of US troops will also make it easier for Iran to strengthen its foothold in Syria and smuggle arms into the country, including weapons designed for Hezbollah.The New York Times reported that anonymous Israeli intelligence officials had said they felt betrayed by the Trump administration, with one official saying that Israel has been thrown under the bus.Knesset Foreign Affairs and Defense Committee chairman Avi Dichter put a positive spin on the Syria withdrawal in an interview with Army Radio on Friday.“There is no doubt that it is always good to have a friend in the region, but the presence of the American army here was not critical for us,” Dichter said. “The US withdrawal can actually give rise to an opportunity to leverage a move to remove Iran from Syria, at least against the Russians.”Former Israeli ambassador to the US MK Michael Oren (Kulanu) tweeted: “Today, as in the past, Israel will have to defend itself with its own forces in order to deal with the great threats in the North.”He thanked Mattis for his commitment to Israeli security. “Mattis believed that a strong American presence in the Middle East served as a buffer to Iran and other hostile elements,” Oren wrote.Trump’s declaration of triumph has alarmed key NATO allies such as France and Germany, who said such a change of course on Syria risks damaging the fight against Islamic State, which has now been squeezed to a sliver of Syrian territory.Iran made its first reaction to Trump’s planned pullout.“From the start, the entry and presence of American forces in the region has been a mistake, illogical and a source of tension, and a main cause of instability,” Iranian Foreign Ministry spokesman Bahram Qasemi was quoted as saying by state media on Saturday.Tehran has opposed the presence of foreign forces in Syria, except those – from Iran and Russia – which have been invited by the government of Bashar Assad.Maghawir al-Thawra leader Col. Muhanad al Talaa, whose several hundred fighters work alongside US troops at the Tanf camp, said although they were notified of Washington’s decision, the situation on the ground remained as it was and that the troops had not yet left.“American troops plan to withdraw completely from Syria but I don’t have details – and things are as they are up until this moment,” Talaa told Reuters from the base.The garrison is located in a strategic area near Syria’s Tanf border crossing with Iraq at the crossroad of a main Baghdad-Damascus highway, Tehran’s main arms supply route by land to Syria and to Lebanon’s powerful Hezbollah militia.Turkey will take over the fight against Islamic State in Syria as the United States withdraws its troops, President Tayyip Erdogan said on Friday, in the latest upheaval wrought by Washington’s abrupt policy shift.For Turkey, the step removes a source of friction with the United States. Erdogan has long castigated his NATO ally over its support for fighters of the Syrian Kurdish People’s Protection Units (YPG) against Islamic State. Turkey considers the YPG a terrorist group and an offshoot of the armed Kurdistan Workers’ Party (PKK), fighting for Kurdish autonomy across the border on Turkish soil.In a speech in Istanbul, Erdogan said Turkey would mobilize to fight remaining Islamic State forces in Syria and temporarily delay plans to attack Kurdish fighters in the northeast of Syria – shifts both precipitated by the American decision to withdraw.A US official, speaking on condition of anonymity, said American troops may continue to operate against Islamic State in Syria. The Pentagon is considering using Special Operation teams based in Iraq to target militants in Syria, the official said.The official emphasized that using special operators on the ground was one of many options being considered, was still in the planning stages and that no final decision had been made.Islamic State launched an attack on Friday in Syria’s southeast against the US-backed Syrian Democratic Forces (SDF) militia, employing car bombs and dozens of militants.“We will be working on our operational plans to eliminate ISIS elements, which are said to remain intact in Syria, in line with our conversation with President Trump,” Erdogan said.Russia said on Friday that it did not understand what the United States’ next steps in Syria would be, adding that chaotic and unpredictable decision making in Washington was creating discomfort in international affairs.Several of Trump’s fellow Republicans in Congress, joined by opposition Democrats, urged the president to reverse course, saying the withdrawal would strengthen the hand of Russia and Iran in Syria and enable a resurgence of Islamic State.Republican Senator Lindsey Graham on Friday called for immediate Senate hearings on Trump’s decision to withdraw all American troops from Syria.Graham, a member of the Senate Armed Services Committee, told reporters he wanted to hear directly from Mattis at any hearing.Trump has given no sign of changing his mind. He promised to remove forces from Syria during his 2016 election campaign.Islamic State launched an attack on Friday on positions held by the SDF in Syria’s southeast and the US-led coalition mounted air strikes in the area, an SDF official said.Kurdish-led forces in northern Syria may not be able to continue to hold Islamic State prisoners if the situation in the region gets out of control after a US pullout, top Syrian Kurdish official Ilham Ahmed said on Friday.