Updated

President Bush's war strategy is failing and the top military commander in Iraq is "dead flat wrong" for warning against major changes, the Democratic chairman of the Senate Foreign Relations Committee said Sunday.

Ahead of two days of crucial testimony by Bush's leading military and political advisers on Iraq, Sen. Joseph Biden indicated that he and other Democrats would persist in efforts to set target dates for bringing troops home.

"The reality is that, although there has been some mild progress on the security front, there is, in fact, no real security in Baghdad or Anbar province, where I was dealing with the most serious problem, sectarian violence," said Biden, a 2008 presidential candidate who recently returned from Iraq.

Gen. David Petraeus and Ambassador Ryan Crocker were scheduled to testify before four congressional committees, including Biden's, on Monday and Tuesday. Lawmakers will hear how the commander and the diplomat assess progress in Iraq and offer recommendations about the course of war strategy.

Officials familiar with their thinking told The Associated Press over the weekend that the advisers would urge Congress not to make significant changes. Their report will note that while national political progress has been disappointing, security gains in local areas have shown promise, according to the officials who spoke on condition of anonymity because they were discussing internal deliberations.

Petraeus and Crocker will say the buildup of 30,000 troops, which bring the current U.S. total to nearly 170,000, is working better than any previous effort to quell the insurgency and restore stability. The officials also disputed suggestions that Petraeus and Crocker would recommend anything more than a symbolic reduction in troop levels and then only in the spring.

The testimony sets the stage for an announcement by Bush later in the week about how he will proceed in the face of widespread public unhappiness and growing congressional discomfort with the war.

Biden, signaling that tough questioning awaits the pair from majority Democrats and moderate Republicans, said Petraeus' assessment missed the point. Biden, D-Del., said focusing on a political solution, such as by creating more local control, was the only way to foster national reconciliation among warring factions.

"I really respect him, and I think he's dead flat wrong," Biden said.

Biden contended that Bush's main strategy was to buy time and extend the troop presence in Iraq long enough to push the burden onto the next president, who takes office in January 2009, to fix the sectarian strife.

"This president has no plan — how to win and/or how to leave," Biden said.

Stressing that a political solution was the key, he said, "I will insist on a firm beginning to withdraw the troops and I will insist on a target date to get American combat forces out," except for those necessary to protect U.S. civilians and fight Al Qaeda.

Sen. John Kerry, D-Mass., agreed. "The problem is, if you don't have a deadline and you don't require something of the Iraqis, they're simply going to use our presence as cover for their willingness to delay, which is what they have done month after month after month," he said.

"I think the general will present the facts with respect to the statistics and the tactical successes or situations as he sees them," Kerry said. "But none of us should be fooled — not the American people, not you in the media, not us in Congress — we should not be fooled into this tactical success debate."

Sen. Arlen Specter, R-Pa., said he respects the judgment of Petraeus but will not blindly follow his assessment.

"We're going to look behind the generalizations that General Petraeus or anybody gives us and probe the very hard facts to see exactly what the situation is," Specter said. "As I've said in the past, unless we see some light at the end of the tunnel here, very closely examining what General Petraeus and others have to say, I think there's a general sense that there needs to be a new policy."

Sen. Lindsey Graham, R-S.C., said it would be foolish for Congress to try and second-guess commanders on the ground.

In the end, Graham said, the U.S. cannot afford to withdraw prematurely if it is military unwise and risks plunging the region into more chaos.

"If the general tells me down the road we can withdraw troops because of military success, we should all celebrate it," Graham said. "But if politicians in Washington pick an arbitrary date, an arbitrary number to withdraw, it's not going to push Baghdad politicians.

"It's going to re-energize an enemy that's on the mat," he said.

Biden spoke on NBC's "Meet the Press," Kerry appeared on ABC's "This Week," Graham was on "Fox News Sunday" and Specter was on "Late Edition" on CNN.