Turkey dispatched a delegation to Moscow on Monday for another round of talks aimed at forging a cease-fire agreement in Syria, where relief agencies warn that a deadly vortex of proxy wars could cause the worst humanitarian disaster in the nine-year conflict.

At stake is control of Idlib province, a patch of land the size of Delaware that is the last stronghold of Turkish-backed rebels resisting the regime of President Bashar al Assad, which is backed by Russia.

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