And since Iraq has no real borders now, I would expect Iran would be plotting to take over Shia dominated Baghdad.
The Shia have been increasing in Baghdad the last 30 or so years and I believe now they are the dominant population of Baghdad.
The Sunnis could flee Baghdad and join with ISIS. -Tom
The Shia represent about 60% of Iraqis and in a country where the central authority controls and runs so much it collects money, power and people to itself - a pattern evident around the world. The general majority demographic - the Shia - becoming the majority in Baghdad is a consequence of their general national majority and the concentration of power in Baghdad.
GWB might have removed Saddam, but the displacement of any Sunni (like Saddam) as head of Iraq was only a matter of time (as it is in other places where self-appointed Sunnis rule over national majorities of Shia).
Unfortunately, a much more true statesman-like “nationalist” head of state, could have started to lessen the Sunni-Shia divisions, but that man was not Maliki.