A senior US intelligence official has warned that Syria has become the "predominant jihadist battlefield in the world." As many as ten thousand foreigners could now be fighting there and the US fears they could return as part of a global jihadist movement that threatens Europe and the United States. There appears to be stalemate on the ground: the United Nations says Syria is "in freefall". HARDtalk speaks to Najib Ghadbian, the UN and US representative of the opposition Syrian coalition. What should he and others do to end the crisis?