A U.S. military convoy withdrawing from Syria for Iraq today was pelted with fruit and stones by Kurdish civilians who accuse the superpower they once saw as their protector of leaving them in peril. Driving the news: “We never agreed to protect the Kurds for the rest of their lives,” President Trump responded back in Washington. He said the U.S. would keep small detachments in Syria at the request of Israel and Jordan and to “protect the oil," but there was otherwise "no reason" to remain."We want to keep the oil, and we'll work something out with the Kurds. ... Maybe we'll have one of our big oil companies to go in and do it properly," Trump said.He also insisted a ceasefire announced from Turkey last week by Vice President Pence was holding despite “some skirmishes.” What to watch: The deal expires tomorrow night and Turkish President Recep Tayyip Erdogan has vowed to resume his offensive if the so-called “safe zone” he’s demanded isn’t cleared of Kurdish fighters. Erdogan will be meeting tomorrow with Russian President Vladimir Putin.According to Brett McGurk, who resigned as Trump’s counter-ISIS envoy over a planned withdrawal last December, it's now "in the hands of Putin" whether "an epic humanitarian catastrophe" unfolds in Syrian border cities like Kobane that had been held by Kurdish forces.Behind the scenes: I asked McGurk today whether he'd ever heard Trump express interest in what would become of Syria after the ISIS caliphate was defeated."He talked about defeating the ISIS caliphate, he takes credit for it, but beyond that I don’t think he has much of a significant concern," McGurk said, speaking at the Foundation for the Defense of Democracies.While the U.S. had several stated objectives in Syria that required long-term commitments — including remaining until Iran was out and the peace process finalized — McGurk said he never heard Trump himself vocalize them.“In fact, he basically says, ‘the Russians and anybody else can do what they want,’” McGurk continuedWhy it matters: “If the president isn’t fully bought into a policy, particularly when it comes to war and peace ... when there's a crisis he’s not going to really have anyone’s back.”Trump did express interest in what would happen to Syria's oil. McGurk said he explored the issue with Rex Tillerson, who was then secretary of state and previously ExxonMobil CEO.Reality check: "I think [Tillerson's] phrase was, 'That's not how oil works,' McGurk said, noting that the oil legally belongs to the Syrian state.“Maybe there are new lawyers, but it was just illegal for an American company to go and seize and exploit these assets."The bottom line: "We don’t want these resources to get in the hands of terrorists or others, but maybe Trump should have thought about this before he basically made a decision that unraveled the tapestry that had been working relatively well," McGurk said.Go deeper ... Expert Voices: Years of muddled U.S. strategy deepened Syria crisis