Patrick Cockburn explains:
When the US and Britain invaded Iraq, they started three wars. The first is the insurgency in the Sunni community against the American occupation; the second the struggle by the Iraqi Shia, sixty per cent of the population, allied to the Kurds, to take control of the Iraqi state, previously controlled by the Sunni; and the third a proxy war between the US and Iran about which of them is to have predominant influence in Iraq.
None is over yet. The third has barely started.