WASHINGTON - The killing of Saddam Hussein's sons could be a double bonanza for the Bush administration if it both weakens armed resistance in Iraq and deflects attention from the Iraq-Niger uranium controversy.

　　But the first challenge may be to prove to the world - especially Iraqis and other Arabs - that Uday and Qusay are really dead.

　　US officials said the pair, feared and hated in Iraq almost as much as their father, were killed in a six-hour battle with 200 American troops on July 22 in the northern city of Mosul.

　　Although President George W. Bush declared major combat in Iraq to be over on May 1, Saddam, his sons and other key aides remained at large - a haunting symbol of unfinished business.

　　In the months since, some 39 American soldiers have been killed in almost daily attacks that have increasingly come to be seen as a guerrilla war of unexpected ferocity.

　　Deputy national security adviser Stephen Hadley, asked if the deaths of Saddam's sons could lead to a reduction in attacks on US soldiers, said: "It's clearly important politically - it's clearly important to send a message to the Iraqi people this regime is not coming back. But it also may have had an operational effect, we just don't know."

　　The deaths were "a huge signal that the United States really is in control of Iraq," said Jonathan Alterman, director of the Middle East programme at the Centre for Strategic and International Studies.

　　"It is a demonstration that the United States can and will track down Saddam" and other top regime figures, he said.

　　Fate of opposition

　　Middle East expert Gary Sick of Columbia University said Saddam, his sons and their close aides, bolstered by US billion in stolen Iraqi funds, were a major force behind continued opposition to US forces.

　　"As long as they are out there, the possibility exists that Iraqis will say 'this group is going to win' and shift to their side. If they are gone, the opposition will be less well-organized and financed and the psychological appeal of the prior regime will be increasingly dissipated," he said.

　　But Kenneth Katzman of the Library of Congress' Congressional Research Service was sceptical.

　　"The guerrilla leaders are fighting for themselves, not necessarily to restore Saddam. They are fighting to end the US occupation and restore a Sunni-led Arab nationalist regime. In fact, some guerrilla leaders may be more energized if Saddam and his sons are not in the picture," Katzman said.

　　A crucial task is to provide proof that Uday and Qusay are really dead, said Professor Richard Russell of the National Defence University.

　　Americans are inclined to give the administration the benefit of the doubt but "in the Arab world and Iraq where rumours reign supreme, it will be hard to prove," he said.

　　Still, the deaths are likely to be a morale boost for US troops dispirited by mounting casualties and the seeming lack of a US plan for post-war Iraq, said former Assistant Defense Secretary Larry Korb.

　　Intelligence row

　　The stunning events in Mosul quickly overshadowed a controversy that has dogged Bush in recent weeks - whether he deliberately exaggerated US intelligence on Iraq's weapons to boost the case for war.

　　He has come under particular fire for a claim in his State of the Union speech, subsequently acknowledged to be false, that Iraq was trying to buy uranium from Niger.

　　The White House press briefing gave the subject short shrift on July 22. Hadley, aware Uday and Qusay's deaths were the day's big news story, took the opportunity to announce that he would share blame with the CIA for the Iraq-Niger mistake.

　　Nevertheless, Saddam still remains at large and the killings of his sons will make little difference until he is caught, said Ivo Daalder, a former Clinton administration official.

　　Daalder, now with the Brookings Institute, said the two deaths would not end the intelligence controversy.

　　"I don't think this makes any difference to the criticism about why we went to war and the criticism about the lack of planning for the post-war period and the real problems we are facing in Iraq today," he said.