Hakim Khatib: Research fellow at the Frankfurt Research Centre on Global Islam at the Goethe University Frankfurt in Gemrany and the editor-in-chief of the Mashreq Politics and Culture Journal.
Analysis: Washington is still weighing up its approach to Syria, but the power balance that Russia, Turkey and Iran have built will not be easy to change.
Analysis: Tensions between the two countries are at their highest level in years, but a military escalation is more likely to have an impact on neighbouring countries, writes Hakim Khatib.