With the ‘Islamic State’ in tatters, President Assad and his allies are looking to restore Syria’s mangled infrastructure, Kurdish forces are also looking to position themselves for the post-war settlement. Euphrates oil fields  where the two sides face each other  are emerging as a source of tension.

After six years of war, the Syrian government finally has more to consider than merely survival. US-backed Kurdish militias and the Syrian Arab Army (SSA) have...