"As for the United States, its knowledge of the opposition is far from complete," said Richard Murphy, who served as US ambassador to Syria and Saudi Arabia under US presidents Richard Nixon and Ronald Reagan.
Murphy, former assistant secretary of state for Near East and South Asian affairs between 1983 and 1989, emphasized that a Syrian opposition is "elusive" and represents a patchwork of groups with disparate agendas for countering Syrian President Bashar Assad.
"It [opposition] consists of many factions which follow their particular plan of how to oppose the regime and which adapt to changing circumstances," he observed.
"Some in the opposition give absolute priority to unseating the regime over targeting ISIL in Syria. This has fostered uncertainty in Washington over how to work with the opposition," Murphy said.
Since the beginning of the Syrian civil war four and a half years ago, the United States and some of its allies have supported what they term a "moderate" armed Syrian opposition faction, which is fighting government forces in the country.
