If Turkey enters into war is NATO still bound by Article 5, the unified defense clause? Could the US even consider not backing up Turkey and Saudi Arabia if they decided to break with the peace process the US set up with Russia?
Next Big Future: Turkey and Saudi Arabia could send tens of thousands of troops into Syria and a possible prelude to full blown Russia-Middle East war
Since the end of WWII there has always been a way to keep from going through with a full scale world war, but sure seems like Syria/ME could set up to test those limits.