[Future Snake Eater]

...to bring about a largely mythical "national reconciliation".

Something that he's barely even attempted. The only thing that can calm this country down. Therefore, he's not worth our effort, neither is this country.

[JasonC]

The country isn't going to "calm down". The Sunni are still not defeated and still do not accept their loss of power. 95% of Sunnis consider the US presence illegitimate and well over 60% support bombing US soldiers. The portion of the population that wants everyone to just keep what they have instead of fighting is about a third, of which a quarter are Kurds in the north not directly involved in the sunni-shia fighting.

Everyone believes the US will leave at the latest by the end of Bush's term, and knows that as soon as we do, the war to control Iraq begins all over again, this time without Queensbury rules. Most of the Shia recognized that the largest power in Iraq as soon as that happens will be Iran, and its clients, the Sadr wing of the Shia.

The only forces inside Iraq willing to fight Sadr, that being the case, are the Sunnis. They expect to be supported with gobs of money by the Saudis. Saudi Arabia and Iran will conduct a proxy war through their clients as soon as the US leaves. Iran is almost certain to win that war.

Petraeus has recently been arming the Sunnis as a means of trying to pressure Maliki, but it will only drive him deeper in the arms of Iran. Maliki is emphatically preparing himself and his party for the time when your conclusion, that Iraq isn't worth it, is acted upon. The result will be first a civil war on a higher level of conflict, second the defeat of the Sunnis without restraint in how they are treated as they lose (which will drive millions into exile in Jordan and Saudi Arabia), and finally Iranian alliance with the new Iraq.