Citing a continued military buildup along their frontier in northern Syria, the Kurdish YPG’s leadership says they believe an attack by Turkey, leading to open warfare, is imminent, and will likely begin “within days.”

Turkey and the YPG are hostile toward one another, with Turkey repeatedly declaring the Kurds “terrorists,” and attacking Kurdish targets in Afrin District. YPG commanders have openly talked about invading Turkish-held parts of Syria and “liberating” them into the Kurdish autonomous region of Rojave.

Turkish Deputy PM Numaan Kurtulmus denied that Turkey was “declaring war” against the YPG, but did insist that they are “making preparations” to protect Turkish independence from the “threat” posed by the continued existence of the YPG on their border.

If fighting does break out, it will likely derail the YPG’s invasion of the ISIS capital city of Raqqa, virtually obliging them to withdraw much of the invasion force to defend their own territory from a Turkish advance. This fear has been foremost in the minds of US war-planners, who have repeatedly tried to prevent the two sides from direct combat situations against one another.