Clausewitz said that warfare is the continuation of policy by other means. “Politcs,” it is said, “is the art of the possible.” In a democracy, the strategic center of gravity – and thus, the fulcrum of national policy – is always public opinion. Taken together, these aphorisms explain why US and the Iraqi Army are busily rooting out Sadr’s Iranian-trained special groups from Sadr City, even if it raises the butcher’s bill, as Michael Yon reports:

April saw 49 U.S. casualties in Iraq, the highest total in seven months. Does this mean, as some insist, that the enormous progress we have made since the start of the military surge is being lost?

As one who has spent nearly two years with American soldiers and Marines and British Army troops in Iraq – having returned from my last trip a month ago – here’s my short answer: no.

We are taking more casualties now, just as we did in the first part of 2007, because we have taken up the next crucial challenge of this war: confronting the Shia militias.

In early 2007, under the leadership of Gen. David Petraeus, we began to wage an effective counterinsurgency campaign against the reign of terror Al Qaeda in Iraq had established over much of the midsection of the country. That campaign, which moved many of our troops off of big centralized bases and out into small neighborhood outposts, carried real risks.

In every one of the first eight months of 2007, we lost more soldiers than we had the previous year. Only as the campaign bore fruit – in the form of Iraqi citizens working with American soldiers on a daily basis, helping uncover terrorist hideouts together – did the casualty numbers begin to improve.

LTGEN Ricardo Sanchez, who oversaw the descent of Iraq from post-phase III turmoil to sectarian bloodbath, recently released his memoirs entitled, “Wiser in Battle: A Soldier’s Story.” In it, and over nearly 500 pages, he relates the Bush administration’s initial eagerness to quell rising lawlessness in Fallujah in the spring of 2004:

Crafted in Washington as a brass-knuckles response to the gruesome deaths of four Blackwater security guards killed the week before and strung up on a bridge, the battle had the full support of President Bush.

Sanchez, in a memoir to be released Tuesday, said Bush “launched into what I considered a kind of confused pep talk” about the battle for Fallujah and an upcoming campaign to kill or capture radical anti-American cleric Muqtada al-Sadr and cripple his militia.

“Kick ass!” Bush said. “If somebody tries to stop the march to democracy, we will seek them out and kill them! We must be tougher than hell!”

The Blackwater contractors will killed on 31 March 2004. On 4 April, two thousand Coalition forces led by the 1st Marine Expeditionary Force encircled the city to pacify it, gradually tightening the noose. Five days later, with roughly a quarter of the city under US control, 21 Marines and hundred of Fallujans dead, L. Paul Bremer declared a unilateral cease fire.

Humanitarian concerns were certainly in play, but the unexpectedly stiff opposition, revolts in Sunni Ramadi and across the Shia south, and lurid images splayed across Arab TV screens by Al Jazeera made political Washington blanch. A full-scale assault on the city while clapping a stopper over Ramadi, rooting the JAM out of Najaf and securing the road to Baghdad International Airport was not a do-able do. Not with the combat power in place, and not with US elections looming.

Although Sanchez claims in his book that US forces did not retreat under fire, the perception in Iraq and elsewhere was that the Sunni “lions of the desert” had inflicted the kind of defeat that Saddam’s secular legions could not. The bill came due on that perception just days after the US elections in November 2004, when a much larger and more deliberate application of firepower rubbled the city and destroyed in detail the resistance forces that had gathered there, albeit at a greater cost.

Was the timing political? Yes, probably. But politcs is the art of the possible, and warfare is policy by other means.

With the Sunni west now not merely pacified but actively assisting in the hunt for Qaedist butchers and Baghdad violence sharply down as a consequence of the surge, the remaining major barrier to lasting peace – and the withdrawal of most US combat power – is the Hezbollah-style alternate government of Sadrists, their militias and the so-called “special groups,” trained by and aligned with Iran.

We are rooting out the Sadrists now because we must – the Iraqi government’s writ must extend over the whole of a federal Iraq, or else there is no government and chaos follows. And because we can – our own attention is riveted to the domestic political scrum, and both Congress and the people know that no change in strategy can be imposed upon this administration: Lame duck governments have little enough leverage, but what they do have is unassailable, and this one has nothing at all left to lose.

Timing is everything: We fight in Sadr City now because we must, and because we can. It was politically impossible before now to implement the national policy of a free, federal and democratic Iraq, secure within its own borders and no threat to its neighbors. But if it says something uncomfortable about our national mood and commitment that we must time our military actions to the domestic political cycle, it also says something uncomfortable about our attention spans that we can.

Still, politcs is the art of the possible. Warfare is policy by other means.