It was a defining moment all right. Mr. Maliki’s impulsive and ill-planned attempt to vanquish the militias in southern Iraq loyal to his Shiite rival, the cleric Moktada al-Sadr, was a failure that left Mr. Sadr more secure than before. Though some Iraqi armed forces were briefly in the lead, others mutinied. Eventually American and British forces and air power had to ride to the rescue in both Basra and Baghdad. Even then, the result was at best a standoff, with huge casualties. The battle ended only when Mr. Maliki’s own political minions sought a cease-fire.

Mr. McCain was just as wrong about Basra as he was in 2003, when he said the war would be “brief” and be paid for by Iraqi oil revenues. Or as he was in the 1990s, when he championed extravagant State Department funding for the war instigator Ahmad Chalabi, who’d already been branded untrustworthy by the C.I.A. (The relationship between Mr. Chalabi and the former lobbyist Charles Black, now a chief McCain campaign strategist, is explored in a new book, “The Man Who Pushed America to War,” by Aram Roston.)

As for Basra, Mr. McCain told Joe Klein of Time in January that it was “not a problem.” He told John King of CNN while in Baghdad last month that Mr. Sadr’s “influence has been on the wane for a long time.” When the battle ended last week, Mr. McCain said: “Apparently it was Sadr who asked for the cease-fire, declared a cease-fire. It wasn’t Maliki. Very rarely do I see the winning side declare a cease-fire.” At least the last of those sentences was accurate. It was indeed the losing side  Maliki’s  that pleaded for the cease-fire.

Perhaps all these mistaken judgments can be attributed to the fog of war. But Mr. McCain’s bigger strategic picture, immutable no matter what happens on the ground, is foggier still. Like Mr. Bush, he keeps selling Iraq as the central front in the war on Al Qaeda. But Al Qaeda was not even a participant in the Basra battle, which was an eruption of a Shiite-vs.-Shiite civil war. (Al Qaeda is busy enough in Afghanistan and Pakistan, the actual central front in the war on terror.)

Mr. McCain is also fond of portraying Mr. Maliki’s “democracy” in Iraq as an essential bulwark against Iran; his surrogate Lindsey Graham habitually refers to Mr. Sadr’s Mahdi Army as “Iranian-backed militias.” But the political coalition and militia propping up Mr. Maliki are even closer to Iran than the Sadrists. McClatchy Newspapers reported last week that the Maliki-Sadr cease-fire was not only brokered in Iran but by a general whose name is on the Treasury Department’s terrorist list: the commander of the Quds force of Iran’s Islamic Revolutionary Guard.

Image Credit... Barry Blitt

So this is where this latest defining moment in Iraq leaves us: with victories for Iran and Mr. Sadr, and with Iraqi forces that still can’t stand up (training cost to American taxpayers so far: $22 billion) so we can stand down. The Baghdad Green Zone, pummeled with lethal mortar fire, proved vulnerable once again. Basra remains so perilous that Britain has had to suddenly halt its planned troop withdrawals. Tony Blair had ordered the drawdown a year ago, after declaring that “the next chapter in Basra’s history will be written by the Iraqis.”