Washington ? The dust having settled – 500-pound bombs can raise, and even manufacture, a lot of dust – it is time to give the devil his due. To understand the diabolical genius of Abu Musab al-Zarqawi, that pornographer of violence, begin with this:

He was a primitive who understood the wired world, and used an emblem of modernity, the Internet, to luxuriate in gore. But although he may have had an almost erotic enjoyment of the gore, it was also in the service of an audacious plan. And he executed it with such brutal efficiency that he became, arguably, the most effective terrorist in history.

That appellation still suits Osama bin Laden because, as the animating mind behind 9-11, he pulled the world’s superpower into a war that provided the occasion for al-Zarqawi’s rise to world prominence. Still, al-Zarqawi set out to prove that a central premise of the U.S. intervention in Iraq was – is – false. Or perhaps it is more precise to say that he decided to make it false. But if he could falsify it, it never was quite true.

The premise was that Iraqis are primarily nationalists and only secondarily sectarians. Al-Zarqawi’s wager was that explosives, used with sufficient cruelty, could blow that premise to smithereens. He may have succeeded. If so, the February bombing of the Askariya shrine, although the blast itself killed nobody, may have been the most deadly explosion since the planes hit the twin towers, because it provoked sectarian violence that may now constitute a social firestorm.

A firestorm occurs when a fire becomes so hot that rising heat pulls in cold air, an influx of oxygen that feeds the fire. A firestorm is self-perpetuating because, in effect, the fire becomes its own fuel. If Iraq’s sectarian violence has reached that point, al-Zarqawi had made himself somewhat superfluous.

It is sometimes charged that journalism, which considers the phrase “good news” an oxymoron (“We do not report the planes that land safely”), is missing the good news from Iraq. But so pervasive is the violence, and hence so dangerous has Iraq become for journalists, that The Wall Street Journal, hardly a hostile observer of the U.S. undertaking in Iraq, thinks the bad news might be underreported.

Even the good news often has a dark cast to it. At last – 25 weeks after the voting – the Iraqi parliament has produced a full government. But its first task is to conquer itself: It must end the sectarian violence by people wearing government uniforms, in the military and police.

It is frequently said that protracted terrorism has an atomizing effect on a polity, reducing civil society to so much human dust. In Iraq it may be having the opposite effect: Rather than disaggregating Iraqis, the force of the explosions – especially the one on Feb. 22 that demolished the dome of the Askariya shrine in Samarra – seems to have blown them together, ruinously, into furious Sunni and Shiite blocs.

Just in May, just in Baghdad, sectarian violence killed 1,400 – and that figure does not include victims of car bombs. It speaks depressing volumes about the U.S. predicament that the new idea is to … conquer Baghdad. On April 20, the Iraq War became as long as the Korean War. This Friday the war will be as long – 1,185 days – as U.S. involvement in the Second World War was when U.S. troops captured the Ludendorff railway bridge at Remagen and became the first foreign troops to cross the Rhine since Napoleon’s in 1805. And Baghdad beyond the Green Zone is a war zone, which accounts for the flight from the country of many educated and mobile Iraqis.

But it did not take three years of al-Zarqawi and terrorism and sectarian violence to turn Iraqis into difficult raw material for self-government. For that, give another devil his due: Saddam Hussein’s truly atomizing tyranny and terror did that. On June 20, 2003, just 72 days after the fall of Baghdad, The Washington Post reported this vignette from Fallujah:

“Military engineers recently cleared garbage from a field in Fallujah, resurfaced it with dirt and put up goal posts to create an instant soccer field. A day later, the goal posts were stolen and all the dirt had been scraped from the field. Garbage began to pile up again.”

An Army captain asked, “What kind of people loot dirt?” There are many answers to that question. Here is one: A kind of people who are hard to help.