US concerns about Iraq's political stability stem in large part, as they have in the past, from unresolved tensions along ethnosectarian divides – between the majority Shiites and the minority Sunnis, but also now between the Kurds and the Shiites.

...Gen. Ray Odierno, the US commander in Iraq who replaced General Petraeus, is speaking publicly of his concern that power struggles exacerbated by the upcoming elections could undo recent political gains.

...these concerns factor into a recent Pentagon assessment of Iraq, which cited a list of unresolved political issues and security question marks. The next National Intelligence Estimate, which will be published sometime after the US elections, is expected to echo the cautious sentiment.

Another troubling development in Iraq – one that has received less attention than the sectarian schisms – is the growing divide between a large and increasingly successful military, and a lagging and increasingly disdained civilian government, says Mr. White, now an adjunct scholar at the Middle East Institute in Washington.

"The civilian side of government is terribly weak, dysfunctional, and corrupt, and against that is this burgeoning national army that has allowed for most of what Maliki has achieved," he says. "We could see a building of resentment within the Army against Maliki for taking the credit while failing to put the civilian side in order – and that could lead to some kind of action by the Army."

Iraq scholars, who point out that a similar widening governmental divide in the 1950s led to a coup against Iraq's monarchy, say that Iraq could end up with the kind of authoritarian military government more typical of Middle Eastern regimes if the civilian government is not able to overcome its divisions.

"Of course it's a worrying gap, because continuing down that road could result in a strongman taking power," says Ralph Peters, a former US Army intelligence officer specializing in the Middle East.