Erdogan not only has been the main supplier of arms to the Islamic jihadists fighting in Syria, he has allowed jihadists from 40 different countries to freely pass through Turkey on their way to Syria, and he is treating the wounded jihadists in Turkish hospitals. Of course, you may remember that Obama used Benghazi as the point of origin from which Ambassador Stevens transferred thousands of weapons to Turkey which they in turn have been supplying to the jihadists.
Erdogan, like Obama supports the Muslim Brotherhood whom they both want to replace Assad in Syria. Having suffered a major blow in Egypt with the ouster of the Muslim Brotherhood leader from power, Obama and Erdogan are desperate to set up a new Muslim Brotherhood base in Syria. Now we know why Obama is suddenly so anxious to bomb Syria, having nothing at all to do with chemical weapons.
h/t Eretz Zen