Conditions in Iraq are now as bad as they were in 2006, at the height of that country’s civil war, according to retired Gen. David Petraeus, who led the 2007-2008 “surge” of American forces that found ways to restore order and defeat al-Qaida in Iraq.

There appears to be plenty of blame all around for this situation, which threatens to undo gains for Iraqi democracy that cost the United States some 8,000 military and civilian casualties and more than $2 trillion in ending a civil war that led to roughly 200,000 Iraqi deaths.

Car bombings and other atrocities are on the rise, some committed by Sunni extremists against Shias and some by Shia extremists against Sunnis.

The most extreme Sunni group, al-Qaida, has re-established base camps on the Iraq-Syria border, where another Arab civil war has helped extremists reorganize and build strength.

Iraq’s Prime Minister Nouri al-Maliki was recently in Washington to seek weapons and propose a new security relationship with the United States to replace the one that the Obama administration allowed to lapse two years ago before the new wave of violence.

Mr. Maliki was on firm ground when he told an audience at the U.S. Institute for Peace in Washington that extremism was spreading in his country and Syria because extremists took advantage of a power vacuum created by the Syrian civil war.

But he failed to acknowledge that his government, by allowing Iran to arm and sustain Syrian dictator Bashar al-Assad, had helped to prolong the Syrian conflict.

Also, since he was asking President Obama for help, Mr. Maliki could not be expected to say the obvious:

The power vacuum in Syria that has revived al-Qaida is a direct result of Mr. Obama’s hands-off policy toward the Syrian civil war.

Meanwhile a bipartisan group of Senate critics of the Iraqi prime minister place much of the blame on Mr. Maliki for renewed tensions in his country.

Two of them, John McCain, R-Ariz., and Lindsey Graham, R-S.C., wrote in a published article that Mr. Maliki had offended the Kurdish and Sunni communities, helping fan extremism. They also blamed President Obama for allowing the U.S. security relationship with Iraq to lapse.

To be fair, Mr. Maliki is somewhat trapped between feuding factions of his government. While Sunnis see him tilted against them, radical Shia leaders allied with Iran see him as too lenient with the Sunnis and Kurds.

Mr. Maliki may be a weak reed, but he is the only Iraqi leader that President Obama can turn to in the urgent business of defeating a resurgent al-Qaida in Iraq and Syria.

It is in America’s national interest to help Mr. Maliki obtain new weapons, fight al-Qaida, restrain radical Shias and rebuild trust with Iraq’s important Sunni and Kurdish communities.