WASHINGTON — The way Peter W. Galbraith sees it, southern Iraq had turned irrevocably toward a form of statehood within days of the fall of Saddam Hussein.

In Karbala, the schools were “redesigned along Shiite religious principles,” Shiite clerics ran rubbish disposal, and Shiite militias — with many fighters from Iran — provided security, recalls Galbraith, who witnessed the changes in mid-April 2003.

A “pro-Iranian theocracy” was thus taking root before U.S. and British forces could consolidate the region, Galbraith argues. Iraqi Kurdistan in the north had more than a decade of semi-autonomy, and an insurgency was rising in pockets of the once-dominant Sunni minority across the middle of the country.

Galbraith and a handful of Iraq-watchers soon declared that the nation’s best hope for stability was a loose federation of its three contesting ethnic and religious regions.

Now, more than four years into the war, the idea of a confederated Iraq is winning some support. Sen. Joseph R. Biden Jr., D-Del., claimed to be “building a consensus in the Congress around a way forward in Iraq” when the Senate voted this fall to endorse Iraq federalism. With Congress split on troop-withdrawal questions and Iraq’s government unable to find national reconciliation, the idea is also a lens on the war-torn nation’s enduring divisions.

A onetime committee staffer to former Sen. Claiborne Pell and later U.S. ambassador to Croatia, Galbraith has visited Iraq and backed the Kurdish cause for more than two decades. He helped to document Saddam’s poison-gas attacks on the Kurds in the late 1980s and filmed episodes of the regime’s suppression of the Kurdish rebellion in 1991. Today, he sees the Kurdish north and the Shiite south as effectively independent regions, with their own dominant political parties, governmental structures and military forces. The makings of a central Sunni region, while more problematic, can be seen in the recent shattering of the Sunni alliance with al-Qaida in such places as the western province of Anbar, according to Galbraith.

A bitter critic of the Bush administration’s conduct of the war, Galbraith said the region with its vast oilfield is destined to remain closely allied with the Shiite regime across the border in Iran — “not exactly the most brilliant strategy” — so the United States must adapt to the fact.

The status of the Sunni Muslim minority — whose elite ruled Iraq for decades — presents the thorniest problem to supporters of confederation, in part because members reside in more than one area and in part because the group lacks ready access to oil wealth. Another puzzle is the capital city of Baghdad, with entrenched settlements of all the major ethnic and religious groups.

The Shiite-led government of Prime Minister Nouri al-Maliki has not been able to push through the Iraqi parliament the reforms that the White House and Democratic congressional leaders deem essential to long-term stability. Chief among those measures is an agreement to share oil revenues in a way that would reconcile large numbers of Sunnis to the new regime and maintain Kurdish support.

Biden, the Foreign Relations Committee chairman and an early supporter of the war who became increasingly disillusioned, has invested his presidential campaign in the federalism plan, but its endorsement by the full Senate owed much to a bipartisan sense of frustration about the course of the war.

Since the Democrats won control of both houses of Congress last year, they have failed in several attempts to impose a schedule of troop withdrawals on Mr. Bush. For his part, the president pressed ahead with the so-called “surge” of about 30,000 extra troops to improve security in Iraq.

Biden has argued that the Iraqi constitution, handily ratified in a national referendum in 2005, allows for just the sort of federalism he envisions. It creates a comparatively weak central government by sharply limiting its powers and specifically permits revisions as a way of drawing support from the Sunni minority.

In late September, his plan reached the Senate floor shortly before the vote that killed the latest effort — by Senators Jack Reed, D-R.I., and Carl Levin, D-Mich. — to set deadlines for U.S. troop withdrawals from Iraq.

The nonbinding Biden measure expressed the Senate’s view that the United States should recommend the division of Iraq into the three federal regions “and urge the Iraqi government to agree upon a law to share oil revenue among them.”

The measure passed, 75 to 23, with a majority of Republicans joining a majority of Democrats in favor — a first among substantive legislative policy measures on war-related issues. Reed and Sen. Sheldon Whitehouse, D-R.I., both voted for the measure.

One GOP opponent, Sen. John Kyl of Arizona, argued that “it would be a mistake for us to be seen as dictating to the Iraqi people.”

Levin, who is chairman of the Armed Services Committee, stressed in an interview his view that the measure dictates nothing to the Iraqis — and in fact makes clear reference to the prospect of constitutional changes to accommodate the Sunni minority.

The U.S. Embassy in Iraq reacted with an unsigned statement of opposition to the resolution, saying in part, “attempts to partition or divide Iraq by intimidation, force or other means into three separate states would cause extraordinary suffering and bloodshed.”

It said “partition is not on the table” in the continuing negotiations over possible Iraqi constitutional changes.

Reed, a longtime skeptic of the idea of a three-region federation, explained his vote for the Biden measure this way:

“I think what’s happening on the ground is that there is a growing disaggregation in Iraq.

“In the south, the British are pulling out and the Shiia are establishing themselves, and in the north the Kurds have their autonomous region.”

Despite continuing disruption in the heavily-Sunni middle of the country, Reed said there were signs of an emerging Sunni consensus. “The Anbar awakening represents sort of a more localized approach to the problems in Iraq,” he said.

But Reed reiterated his longstanding concern about the difficulty in striking an oil deal acceptable to all parties. “If the central government can do that, there’s a strong argument that maybe the central government can do other things.”

More ominous than the haggling over oil, Reed said, was the escalating tension between Turkey and Iraqi Kurdistan over the incursions of Kurdish rebel groups into Kurdish population centers across the border in Turkey.

Turkey’s warnings of possible retaliation illustrate how regional federalism “not only might cause problems with stability inside Iraq but it also might prompt neighbors to take more aggressive action when they see their interests challenged.”

Whitehouse said the chief asset of regional federalism is that it would “create a structure” for Iraq’s future. But he warned that no structure could undo “multiple millennia of rivalry and hatred.”

jmulligan@belo-dc.com