Just over a year after the Turkish air force ambushed and shot down a Russian bomber in Syria
Russia and US both have been flying in support of Turkish troops outside the northern Syrian town of al-Bab.
Except now the Americans have gone from flying novel "show of force" missions to actually striking ISIS.
The Russians meanwhile have begun to carry out joint missions with the Turkish air force. Reportedly in the first one 9 Russian and 8 Turkish planes struck ISIS together.
This is just over a year after Turks ambushed and shot down a Russian Su-24 on the Syrian-Turkish border in November 2015 which sparked a massive crisis in relations along with Russian sanctions against Turkish food-growers and tourism.
Now however we have Americans, Russians, Turks and Brits all bombing ISIS in the same area in support of Turkish army and Syrian rebels in Turkish employ. And a historic first -- Russia planning and executing combat action together with a NATO member.