The rising optimism that enveloped the Pentagon last spring about victory in Iraq has given way to more sober assessments that the insurgency will stay somewhat robust for months or years to come.
Spot interviews with mid- and senior-level military personnel reveal a grudging acknowledgement that the two-prong enemy -- Abu Musab Zarqawi's foreign terrorists and Saddam Hussein loyalists -- remains potent despite battles in which scores of fighters are killed or captured.
A senior Pentagon official who monitors daily intelligence reports on Iraq was asked whether the U.S. is winning.
"Good question," the official said. "It's open to discussion." The official spoke as the death toll among U.S. troops topped the 1,900 mark.
The insurgency's resilience is one reason the Bush administration shifted its message this summer, the source said. The new talking point became that the U.S. alone cannot defeat the insurgents and that the Iraqi people in the end must do the job.
Yet inside the Pentagon, and among field commanders, there is a firm belief that Zarqawi is growing desperate.
He is increasing attacks on Shi'ite markets, mosques and neighborhoods to try to incite a civil war between Shi'ite Muslims and dethroned Sunnis, who ran Iraq under Saddam's rule. But in the process, Zarqawi is alienating the very Shi'ites who, like the terror master, want American troops out now.
"You don't see Zarqawi attacking Americans," said a special-operations officer who has debriefed commandos returning from Iraq. "He is so desperate and twisted he's attacking Shi'ites."
A second Pentagon official said intelligence reports show that militant Shi'ites increasingly see Zarqawi as an enemy, not an ally.
"Shi'ites are rapidly concluding that al Qaeda is serving no purpose," the official said. "I read the intelligence. Shi'ites are saying, 'If you want the Americans out, get rid of al Qaeda.' It seems to be turning against [Zarqawi]."
Pentagon officials were quicker to express optimism last spring, as the number of overall attacks dropped and Zarqawi seemed to be running out of steam. But then over the summer, his network unleashed a series of powerful suicide car bombs across the country. Al Qaeda got better at recruiting jihadists and building bombs. The lull gave way to a bloodbath.
Retired Air Force Lt. Gen. Thomas McInerney, an author and TV military analyst, remains confident of victory. He views Iraq as a pivotal battlefield in the ultimate destruction of al Qaeda.
He said Zarqawi's recent pronouncement that he is willfully killing Shi'ite civilians shows the insurgency is in its "last stages."
"There is no rationality to do that if you want to win the hearts and minds of the Iraqi people," he said. "Why would you slaughter them and openly tell them that? That is another strong sign the insurgents are losing."
A new piece of evidence of al Qaeda's decline in Iraq is a letter from Abu Zayd meant for Zarqawi. Zayd was Zarqawi's commander in northern Iraq until coalition troops killed him in recent weeks. The letter was found on his person.
Zayd complained of deteriorating conditions for al Qaeda in Mosul, Iraq's third-largest city. He said al Qaeda was unable to carry out attacks and blamed it on the incompetence of "emirs" who lead groups of terror cells. The letter was translated into English from Arabic by the Pentagon's Defense Intelligence Agency.
Among Zayd's complaints:
"The Emirs hold on to power until their capture or death and refuse to designate a successor, despite their incompetence."
"The lack of diversity in the attacks and the unwillingness to go after the centers and headquarters especially when they are easy targets, and being content with sending suicide bombers after armored vehicles."
"The absence of any legitimate organization in Mosul, in spite of the presence of rightful knowledge-seekers in Mosul."
"Squandering the Muslims' money on petty expenses, cars and phones."
"Reports to the sheikh [Zarqawi] about the situation in Mosul are inaccurate and blurred."