turkish-backed separatists in the north saw an opportunity given russia's distraction in ukraine and iran's reeling from israel's strikes on its proxies, and they went for it. they achieved unexpected success because the syrian army has offered almost no resistance so far. israel and the us are backing them with intelligence and air support, because they want assad gone since he's aligned with iran; turkey wants him gone because they have millions of syrian refugees that they want to gtfo out of turkey
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