Bush’s babble about Iran has taken on a darker tone of late. Just a couple of days ago, the president claimed with certainty that an elite Iranian unit had been supplying Shiite militias in Iraq with deadly weaponry.

He acknowledged a rare bit of uncertainty over whether the Iranian government had ordered the weapons transfer, but added this: “We do know that [Iranian weapons are] there and I intend to do something about it. And I’ve asked our commanders to do something about it.

Oh, dear. Sounds like the administration is cooking up a scheme to engage the Iranian military in hostilities. That makes zero sense.

I’m no expert on Iraq, but I do know this. The country is riven by at least two more or less distinct conflicts: the Shiia-Sunni civil war, and the anti-U.S. insurgency.

The latter is a largely Sunni phenomenon. With the 2003 invasion, the U.S. pushed the Sunnis out of power and “liberated” the Shiite majority, who now control the central government. The anti-U.S. resistance has been largely Sunni-led.

The question becomes, who is funding the Sunni insurgency? Probably not U.S. arch-enemy Iran; that nation is populated, and controlled, mainly by Shiites.

More likely, the money that’s bolstering the resistance is coming from staunch U.S. ally Saudi Arabia. The Saudi government is Sunni-dominated and has already publicly announced its intention to fund Sunni militias if Bush can’t bring the Shiite government to heel.

Moreover, according to Salon, “Many young Saudis have gone to Iraq to become martyrs in the fight against the United States and the Shiite-led Iraqi government.”

It will be remembered, I hope, that Bush marketed the Iraq war as a response to the Sept. 11 attacks. He never explained why invading Iraq made sense as a response to a crime committed largely by a bunch of Saudis.

Now, he seems to be gearing up for a move to attack Iran, even though, again, the real problem seems to lie in Saudi Arabia.

It’s hard to figure out what he hopes to achieve from such a move, beyond yet more chaos and killing.

Enough. It’s time for Congress to defund the war, and demand a regional summit aimed at ending the Shiite-Sunni conflict that Bush seems bent on escalating.