I flew Kyiv Borispol (Ukraine, KBP) to Tehran (Iran, IKA) recently, and our flight went over the northeast tip of Iraq. Normally the flight (Ukraine 751) flies close, but not over, Iraq - around 33 miles from the border [0]. In my case, however, because of harsh weather we went over Iraq for a bit, which was definitely interesting. I know Iraqi airspace isn't the same as Syrian airspace, but it's definitely pretty damn scary being a few minutes' flying time from ISIS strongholds.

[0] https://flightaware.com/live/flight/AUI751/history/20170104/...