geneva syrian government delegation return geneva sunday resumption talk unite nations mediator staffan de mistura week absence western diplomats voice scepticism willingness engage bashar al-ja afari syria ambassador u.n. chief negotiator talk aim find political solution end nearly seven-year-old war land snowstorm flight beirut reuters reporter board say ja afari decline comment de mistura convene eighth round separate talk government unify opposition delegations nov. 28 focus constitutional reform well elections ja afari arrive day late leave two days say opposition mine road talk insist president bashar al-assad could play interim role syria political transition de mistura tell reporters last thursday would assess week whether either side try sabotage process opposition extremely constructive will get senior western diplomat say difficult place criticize internally pressure fact regime bomb away eastern ghouta place diplomat tell reuters government failure return schedule dec. clear sign interest engage political process russian president vladimir putin suggest hold syrian congress russian city sochi early 2018. diplomats see plan bid draw line war celebrate moscow role power tip balance war become key player peace process syrian government return geneva talk western envoys skeptical