The top aid official at the United Nations gave a gloomy assessment of the Syria relief effort on Monday, saying no convoy deliveries had been made to besieged areas this month and that the suffering in Aleppo, once Syria’s commercial epicenter, was the “apex of horror.” In a briefing to the Security Council, the official, Stephen O’Brien, the under secretary general for humanitarian affairs, said that while he welcomed Russia ’s support last week for a 48-hour cease-fire in Aleppo — as he had proposed earlier in the month — there had been no assurances from other combatants. “This cannot be a one-sided offer,” Mr. O’Brien said. “Plans are in place, but we need the agreement of all parties to let us do our job.” United Nations officials have said that the fighting in Aleppo — pitting Syrian government forces and their Russian backers against an array of insurgents, […]