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Americans are dying almost daily in Iraq more than two months after President Bush declared that major combat had ended, and many people believe the anti-occupation violence will persist — or even grow — as long as Iraqis think Saddam Hussein (search) might return.

The resistance, which one U.S. general said Monday has become more sophisticated, has been so persistent that plans for sending U.S. troops home have been thrown in doubt.

U.S. officials have responded not only by putting more U.S. troops on the offensive in pursuit of former Baath Party (search) leaders and other Saddam loyalists, but also by escalating the psychological battle for the hearts and minds of ordinary Iraqis who think Saddam might re-emerge.

One approach is to repeat over and over the assertion that Saddam's reign has ended. Lawrence Di Rita, a spokesman for Defense Secretary Donald H. Rumsfeld (search), made that point Monday.

"There's going to be more violence and other setbacks, there's no question about that," he told reporters. "But make no mistake: Saddam Hussein's regime is gone and it is not coming back."

In a similar vein, the top U.S. administrator in Baghdad, L. Paul Bremer, announced Monday that Iraq's currency, the dinar, will be replaced with new money that does not feature Saddam's image.

Still, Saddam's shadow lingers.

Last week the Arab television network al-Jazeera aired an audiotape of Saddam that CIA analysts say was probably authentic. It was said to have been recorded June 14; if true it would mean Saddam survived the war and may be directing the insurgency.

In Saddam's hometown of Tikrit, someone recently wrote graffiti on a wall of one of his former palaces offering praise for the former president, and no Iraqi has been bold enough to erase it.

Last week, the U.S. government put a $25 million bounty on Saddam's head, and offered $15 million for each of his sons, Odai and Qusai.

Since Bush declared on May 1 that major combat in Iraq was over, 29 U.S. troops have been killed by hostile fire and 44 others have died in accidents and other non-hostile circumstances, a total of 73. On Tuesday, at least seven U.S. troops were injured in numberous attacks.

In the approximately three weeks of fighting before Baghdad fell to U.S. troops on April 9, 102 Americans died, including 87 killed by hostile fire.

Emad Dhia, an Iraqi-American who returned to his homeland after the war to advise the occupation administration, told reporters at the Pentagon on Monday that attacks on Americans will not stop "as long as Saddam's remnants exist." He added: "They will stop at nothing to regain their power."

In Dhia's view, most ordinary Iraqis despise Saddam and are eager to put the past behind them, although the audiotape that surfaced last week was not helpful.

"It will inflict more fear in some of (the) Iraqi people's hearts and minds," Dhia said.

Michael O'Hanlon, a defense expert at the Brookings Institution, believes that questions about the fate of Saddam are not the main problem facing the U.S.-led occupation forces.

"The most important issue is simply that there are a lot of former Baath Party people who have no interest in cooperating with a new Iraqi government" — whether Saddam is around or not, he said.

O'Hanlon believes an Iraqi insurgency could develop more readily from frustration at the slow pace of economic and political reconstruction than a fear of Saddam returning.

Anthony Cordesman, an expert on the Iraqi military and an analyst at the Center for Strategic and International Studies, said he wonders how long the United States can "sit on a hostile Iraq" without addressing the reasons many Iraqis feel alienated by the American occupation and without making it clearer to ordinary Iraqis how they will regain control of their country.

"The administration failed to create any clear plans for conflict-resolution" and underestimated the level of resistance once Saddam was toppled, he said.

U.S. military authorities say they have no good evidence that Saddam was killed in the war, but they also doubt he is orchestrating the wave of attacks on Americans.

Maj. Gen. Carl Strock, deputy director of operations for the U.S. occupation authority, said in a video teleconference from Baghdad that although it is not clear who is directing the attacks, they are becoming more sophisticated.

"I think what's really happening here is that after the cessation of hostilities, the enemy has had a little bit of time to regroup, so we're seeing more deliberate types of attacks," he told reporters at the Pentagon.

"We are not seeing any sort of central or national orchestration of those, but we do see more sophisticated attacks — a combination of explosive devices and direct fire, for example." He also said U.S. forces are using information provided by ordinary Iraqis to ferret out the insurgents.

"We're not sitting still and waiting for them to come to us," he said. "I think that's part of the reason you're seeing an increase in the number of attacks" on American troops.

There are about 146,000 U.S. troops in Iraq.