What\\\'s happening in Iraq?

The Iraq created in large part by the United States after the 2003 invasion appears to be collapsing.

The U.S. military disabled Saddam Hussein's forces in short order. Then the straightforward part of the war ended. The American-led Coalition Provisional Authority made some fateful choices soon after Saddam's government collapsed: to disband the Iraqi Army - one of Saddam's main methods of keeping the nation together - and remove all Baathists from the government. Since the Baathists previously had a monopoly on power, they were the only ones who knew how to keep the country running.

Those factors, among many others - the withdrawal of the restraining hand of the U.S. military, a Shi'ite-dominated central government that has squeezed out the minority Sunni, and a largely sectarian Syrian civil war across an undefended border - are now playing out as Islamist insurgents sweep across the country in a massive offensive that has encountered minimal resistance from the reincarnation of the Iraqi Army.

You can learn who's who in the battle here, and what the insurgents - known as the Islamic State of Iraq and the Levant (known as ISIL or ISIS) - want here.

One way of understanding the conflict is that it's the continuation of the centuries-long battle for control of the Middle East between the Sunni and Shi'ites, Islam's two main sectarian groups. An article in Foreign Policy frames the situation as the clash of proxies for Iran, with its overwhelmingly Shi'ite population, and Saudi Arabia, which is, in many ways, the leading Sunni power.

Things have gotten so serious, apparently, that Iran is even considering banding together with that "Great Satan," the United States, as Reuters reports exclusively.

So, what can be done about the situation in Iraq?

Not much, at least as far as Washington is concerned. Even the air strikes that the Obama administration is considering aren't likely to change the situation on the ground, according to another analysis.