While the desperate flight of Syrians from their country's war was dominating news bulletins this summer, yet another diplomatic push to end the 4-year-old conflict was quietly running into the sand.

That largely unnoticed failure has reinforced the view amongst Syria experts that there is no solution in sight, with one of the biggest obstacles a seemingly unbridgeable international divide over President Bashar Assad's future.

As a consequence, Syria looks set for ever greater fragmentation into a patchwork of territories, one of them the diminishing Damascus-based state where Assad appears confident of survival with backing from his Russian and Iranian allies.