Efforts to end the conflict in Syria have been dealt a serious blow by the resignation of the joint UN-Arab League envoy.
 
Veteran diplomat Lakhdar Brahimi is the second man to leave the job - and there are now questions about how effective a divided UN Security Council can be.
 
Al Jazeera's Kristen Saloomey reports on how Ban Ki-moon, the UN secretary-general, is coming under increased pressure.

Source: Al Jazeera