Even as top Turkish officials excoriate the United States for supposedly backing the failed coup attempt against President Recip Erdogan, Turkish troops, and US Special Forces are coordinating with Syrian Islamist rebels to carry out a de facto invasion of Syria. Under the pretext of fighting the Islamic State, Erdogan's Janissaries, thousands of "Free Syrian Army" jihadis, and 300 US "advisors" are moving to consolidate control over a large swathe of Syrian territory along the Turkish-Syrian border. The government of Bashar al-Assad immediately denounced the move as a "blatant violation" of Syria's sovereignty.

Syria's four-sided civil war just got more complicated – and much more dangerous.

The invasion commenced hours before the arrival of Vice President Joe Biden in Turkey, where he is on a mission to appease the cantankerous Turks. As an official traveling with Biden put it: