The YPG, supported by US airpower had bravely fought the IS, liberating Rakkah from that terrorist group's control. But the present situation is different. Turkish military is a force to be reckoned with. And the US cannot bomb its Nato ally. All the State Department could say in its reaction to the Turkish offensive was to urge it to "exercise restraint and ensure that its military operations remain limited in scope and duration and scrupulous to avoid civilian casualties." The US along with France and some other Western governments also tried to justify the decision to train and arm a new Kurdish force as they advised all parties to remain focused on the central goal of defeating the IS. But to Ankara, creation of a Kurdish 'Border Security Force' is a step towards the establishment of a Kurdish state. There is no way either Turkey or Syria would allow such a state amidst them.
For his part Syrian president Bashar al-Assad, angry over Ankara's support for the rebel 'Free Syrian Army', has denounced the military incursion as "brutal Turkish aggression". He is more worried though about the implant of an American sponsored Kurdish force on Syrian territory, terming it "blatant assault" on his country's sovereignty - whatever is left of it. Not surprisingly Russia, deeply involved in the Syrian conflict is concerned, too, over both the US' move and Turkey's military response to it. It had urged Ankara to stay its attack, offering help to deal with the situation. But President Recep Tayyip Erdogan was determined to smother what he described as a "terror army". With or without UN intervention, Ankara will stop its military action after the achievement of its objective, which is to establish a 20-mile security zone. But any US attempt to surreptitiously install a Kurdish state in Syria next to Turkey will face fierce resistance, further deepening the conflict in that war-devastated land.