The US has approved plans for a series of strikes onbr Iranian targets in Syria and Iraq.br Iran denies direct involvement in the drone attack -br but there are a number of pro-lranian militias based inbr Irag, Syria, Lebanon, the Palestinian territories and asbr far south as Yemen. With all opposed to Israel and thebr United States.br The BBC's Analysis Editor, Ros Atkins, takes a closerbr look at what we know about Iran's alliances.