'Syrian Air Force had bombed ISIS troops on the Iraq side...'

"... Witnesses from another border town, Al Waleed, said the Syrian Air Force had bombed ISIS troops on the Iraq side who were trying to capture it.
If Al Waleed fell, that would leave the Iraqi government without control of a single border crossing to Syria and would deal a blow to both Syria and Iraq. A loss of control over the border would allow ISIS, which has been fighting the Syrian government for months, to move fighters and equipment more freely between the two countries.
The militants are trying to create an Islamic caliphate in a vast area of both countries, wiping out the border in between. Syria’s reported involvement on Saturday was the manifestation of the increasingly convoluted politics surrounding the region. Although the United States argues that President Bashar al-Assad of Syria must step down, he and the United States now have a shared enemy in ISIS..."