GENEVA — Senior diplomats from the United States, Russia and the United Nations failed on Tuesday to agree on a date for convening a long-awaited peace conference aimed at settling the Syria conflict, acknowledging it would not take place this month and possibly not this year. The diplomats adjourned after meetings in Geneva that could not resolve the most basic obstacles: which countries would attend such a conference, who would represent the fractious Syrian opposition and what role — if any — would be played by President Bashar al-Assad of Syria, whose polarizing effects have proved among the most difficult issues to overcome. Lakhdar Brahimi , the United Nations special envoy on Syria, told reporters: “We were hoping that we would be in a position to announce a date today. Unfortunately we are not.” He added, “We are still striving to see if we can have a conference before […]