When Barack Obama replaced George W. Bush in the White House US strategy in the Middle East changed - hubris was out, humility was in. But as the region has sunk deeper into violence, extremism and sectarianism, President Obama's limited ambitions have been condemned by critics as a dangerous form of weakness. Stephen Sackur speaks to Philip Gordon, who has just left his role as the White house's co-ordinator for Middle East policy. What happened to American leadership in a troubled region? Show less