"There is no military solution to a problem like that in Iraq, to the insurgency of Iraq," Petraeus said.
Political progress would require talking with "some of those who have felt the new Iraq did not have a place for them".
He said a key challenge for the Shi'ite-led government of Nuri al-Maliki was to identify those militant groups who were "reconcilable" and to bring them into the political process.
Essentially, Petraeus has explained, in crystal clear times, why the surge won't work and won't bring an end to the war in Iraq. This is an unexpected and remarkably straightforward assessment of the situation that will no doubt have surge supporters squirming in their seats.
In the absence of a political reconciliation between the majority Shia and minority Sunnis, there really is no way to halt Iraq's slide into civil war and chaos. Talks on amending the Constitution stalled long ago and there is zero prospect of their revival.
Meanwhile, Maliki's fragile coalition government is beginning to crumble.
A Shia Islamist party formerly allied to Nouri al-Maliki, prime minister, withdrew from Iraq's ruling coalition on Wednesday, declaring itself ready to join other groups to form a cross-sectarian alliance.
...it does indicate the long-term weakness of Mr Maliki, who is accused both of running a government that only looks out for Shia sectarian interests, and of selling out the Shia under pressure from the US and Sunni community.
Rumors are flying that Iyad Allawi is trying to assemble a coalition to replace Maliki's government. A power struggle if it were to erupt at this point in time would be an enormous setback to US efforts to bring security and stability to Iraq. We could face the prospect of more months of squabbling and back-stabbing similar to what we saw after the last elections.
The bottom line is that the surge isn't working and it won't work. The only solution to Iraq's problems is political and the progress on that front is dismal.
