Syrian regime soldiers began moving north last night to confront the Turkish forces that have invaded northern Syria, adding to growing chaos in the area that analysts fear could spiral into a far wider confrontation.

The US announced it was starting to withdraw its remaining 1,000 troops from the country; an unexpected retreat, and an example British and other western powers are likely to follow.

The decision followed the realisation in Washington that Turkey is intending to go farther in its drive to oust the Kurdish-led Syrian Democratic Forces than had been expected. Turkish forces were last night moving well beyond the border towns of Ras al-Ain and Tal Abyad, their initial targets.

The defenders, the YPG Kurdish militia that is the vanguard of the