The death of Saddam Hussein's two eldest sons in the northern city of Mosul is the best news Washington and its allies have had out of Iraq since the war formally ended three months ago.

But given the resistance the United States is meeting as it ploughs towards its professed goal of a democratic, federal, multiethnic Iraq, it may be the last good news for some time.

The departure of the Hussein brothers is a good thing because of their atrocious records and because, it's hoped, it may reduce attacks on the occupation forces and hence US casualties. Because of their potential impact on domestic opinion, American casualties have the capacity to sap US determination to stay the course in Iraq for what may be the four or five years necessary to establish a democracy.

But even if the deaths of Qusay and Uday do dampen Ba'athist Party resistance, the fact that their father remains at large means the last stand in Mosul is only one more step in the campaign to destroy Saddam Hussein's power - which wasn't even expected to survive the end of the war proper.

And while an imperative, the de-Ba'athification of Iraq is still only preparation for the far more ambitious project, the construction of a new Iraqi polity.

Last week the occupying authorities took a first step by unveiling the somewhat misleadingly titled Iraqi Governing Council.

Given Saddam Hussein's poisonous legacy of ethnic conflict between Arabs and Kurds and sectarian conflict between Sunnis and Shiites, hopes that social and economic structures could be rapidly erected have proved optimistic.

The hand-picked IGC - which includes a significant number of Shiites - is realistically the most representative body Iraqis are likely to get in the near future.

But, the fact that hardline Shiite clerics have rejected the IGC is an indication of the difficulties ahead.

Meanwhile although George Bush, Tony Blair and John Howard are doubtless jubilant at the unexpected news from Iraq, the death of the brothers does nothing to clear the air over the role of the intelligence services in the rush to war.

The Bush administration has found a partial solution in the acceptance of responsibility by a mid-level official for use of the discredited Niger uranium information, and Mr Blair is flying home to face the Hutton inquiry.

But until the question of accountability over the use of dubious material is resolved in what was essentially an information campaign against Baghdad, efforts by Washington, London and Canberra to convince the international community of their bona fides will remain under a cloud.