After two decades as a diplomatic troubleshooter in hotspots from Afghanistan to Iraq, Lakhdar Brahimi firmly believes that every conflict can be solved.

That conviction will be put to the test in his new job as the joint United Nations-Arab League special envoy charged with trying to succeed where his former boss Kofi Annan failed — bringing an end to the 18-month conflict in Syria.

"I think his biggest challenge is convincing the international community to intervene and end this — whatever it takes, because non-intervention has a much higher cost than intervention," Nadim Shehadi, a Middle East expert at London's Chatham House think tank, said in a telephone interview Friday. "Leaving this to go on is going to create more sectarianism, more extremism and more spillover to the region, and the Assad regime is capable of anything to stay in power."

Brahimi brings a unique background and a wealth of experience to a task that many leaders and pundits have written off as impossible.