Kofi Annan, the outgoing UN-Arab League special envoy to Syria, has called his job "mission impossible". So what hope is there that his replacement, Lakhdar Brahimi, can succeed in bringing an end to the violence in Syria?
"Brahimi has a very good background, political background ... and in continuation of this mission .... We have [the] right person [at the] right moment in Syria to fulfill this very difficult but not impossible task [to end the violence]."
- Vyacheslav Matuzov, a former Russian diplomat and chairman of the Russian Friendship Society with Arab countries
The UN admits both sides appear to be set on war, yet Brahimi, the Algerian diplomat, believes every conflict has a solution.
Brahimi is taking over from Annan a day after the UN Security Council ordered its UN observers out of Syria. Members of the UN team based in Homs have been making their way to their headquarters in Damascus from where they will leave the country.
The UN originally sent 300 unarmed military observers to Syria in April, but escalating violence has made their job increasingly dangerous. The 15-member Security Council decided not to renew their mandate, which ends Sunday.
The UN said it wants the mission to be replaced by a liason office in Syria to support any future peace efforts.
"The problem is there isn't any interest on the part of the regime, in particular, and because of that on the part of the various opposition groups in Syria, in actually having a negotiation. The Syrian regime ... have a narrative which is that they are facing a foreign terrorist menace which must be crushed and in the meanwhile they will engage in whatever reforms that they feel are 'appropriate'. Now that is not the basis for any kind of negotiation .... [So] Mr Brahimi will also be facing mission impossible until the situation on the ground changes. "
- Hussein Ibish, a regular contributor to Foreign Policy, The Atlantic and Al Hayat
Back in March, Brahimi's predecessor, Kofi Annan, brokered a ceasefire and a six-point plan to lead to peace talks.
The ceasefire never took hold and two weeks ago Annan resigned saying continued fighting and the lack of unity in the Security Council prevented him from getting his job done.
Although Lakhdar Brahimi is embracing the challenge he has already warned that there is little he can achieve without unity from the UN Security Council.
He has pushed for a new mandate and title and his smaller mission will focus on political affairs.
Brahimi is used to being flown into trouble zones to mediate. The Algerian represented his country's independence movement overseas before joining the Arab League in the 1980's, when he brokered an end to the civil war in Lebanon.
In 2001, he became then UN chief Kofi Annan's special representative, speaking on behalf of the agency at the height of the wars in Afghanistan and Iraq.
But his reputation for being blunt put him at odds with the US government.
After his retirement in 2005, Brahimi became a member of The Elders, a group of former world leaders working for global peace that includes Nelson Mandela.
Since then he has quietly been called upon for his skills and expertise. But at the age of 78, bringing a political solution to Syria could be his biggest challenge yet.
With no political process, what can Brahimi do to succeed where Annan failed?
Inside Syria, with presenter Laura Kyle, discusses with guests: Hussein Ibish, a regular contributor to Foreign Policy, The Atlantic and Al Hayat; Vyacheslav Matuzov, a former Russian diplomat and chairman of the Russian Friendship Society with Arab countries; and Mahjoob Zweiri, a professor of Modern and Contemproary History of the Middle East at Qatar University.
"First we have to say that he is very courageous to accept the job, which is nearly an impossible mission. The idea is to have somebody who could be able to really re-launch a negotiation, if there is any prospect of a negotiation. But obviously for the moment, the two sides have decided to fight."
Gerard Araud, French ambassador to the UN and president of the Security Council