This was supposed to be the month when President Bush began to outline his domestic agenda for a second term, but as he campaigns in advance of his national convention, his message remains elemental: He is the candidate who will keep the country safe.

With a television ad unveiled Wednesday that summons memories of Sept. 11, 2001, and the passion he exhibits over Iraq at his rallies, Bush continues to make his leadership in the war on terrorism -- and what he calls rival John F. Kerry's equivocation -- the dominant argument in his reelection strategy.

The president's handling of the war on terrorism long was seen as his strongest political attribute. But as fighting continues to flare in Iraq and the report of the independent commission that investigated the Sept. 11 terrorist attacks raises questions about the government's readiness to prevent acts of terrorism, Bush finds himself in a battle with Kerry over national security.

It is a fight he comes to with relish, as he showed again here Wednesday while campaigning with Sen. John McCain (R-Ariz.), challenging Kerry's positions on Iraq and sharply questioning his statement that he would withdraw U.S. troops within six months. But even as Bush continues to defend his decision to go to war in Iraq and argue that taking the fight directly and aggressively to the terrorists is the only way to keep America safe, some Republicans question whether this will be the clear-cut winning issue it once appeared to be.

"It is much more of a mixed message than a winning message that it was," said one GOP strategist, who asked not to be identified in order to speak more openly about campaign tactics.

The campaign's newest TV ad underscores the centrality of terrorism in the president's message. Bush is seen on camera with Laura Bush at his side, and the ad opens with the president saying, "My most solemn duty is to lead our nation to protect our citizens." Then he pivots to the Sept. 11 attacks. "I can't imagine the great agony of a mom or a dad having to make a decision about which child to pick up first on September the 11th," he says. The ad concludes with Bush saying, "We cannot hesitate; we cannot yield. We must do everything in our power to bring an enemy to justice before they hurt us again."

Kerry campaign advisers see Bush's reference to Sept. 11 as a sign of weakness and as an effort to rekindle the support for the president that existed at the time but which has faded in the aftermath of the Iraq invasion. "I think the president and his campaign are floundering and in search of a strategy," Kerry adviser Tad Devine said.

Bush's advisers say that far from floundering, and Bush's emphasis on Iraq and terrorism in his campaign speeches reflect the president's belief that terrorism has fundamentally changed the duties of whomever occupies the Oval Office. "The president doesn't think there's anything more important in what he does than keeping the country safe," campaign manager Ken Mehlman said.

A Washington Post-ABC News poll taken after Kerry's convention showed the challenger leading Bush on who would make a better commander in chief, but Bush advisers said they are confident that, in the end, voters worried about security will pick Bush in November, and the president is taking his case directly to the voters.

On his campaign swing this week, the latter part of which is taking him into southwestern and western states Kerry recently visited, Bush has accused his challenger of another change of heart on the wisdom of going into Iraq. Kerry said Monday that knowing then what he knows now, he still would have voted to give Bush the authority to go to war, but questioned why Bush went to war without more international support.

Campaigning in Missouri on Wednesday, Vice President Cheney said he would not trust the four-term Massachusetts senator to make decisions about going to war. "We don't want to turn that responsibility over to somebody who doesn't have deeply held convictions about right and wrong," Cheney said. "And I must say, I look at the record of our opponents. There is a lot of hesitation and uncertainty."

To reinforce the point, the Bush-Cheney campaign released a statement from the vice president in which he said Kerry "has had some difficulty explaining where he stands on the liberation of Iraq."

Bush advisers said the new ad, in revealing how personally Bush feels about the terrorism, underscores the president's commitment to help government combat terrorist threats. The ad, however, makes no mention of governmental changes for fighting terrorism, including those recommended by the Sept. 11 commission.

But Democrats see Tuesday's nomination of Rep. Porter J. Goss (R-Fla.) to be CIA director as an effort by Bush to demonstrate that he is taking more steps to keep the country safe and they say he is driven by polls showing he has slipped on national security issues.

Bush advisers said the continued focus on terrorism is not inconsistent with their earlier statements that the president would use his speech at the Republican National Convention and the weeks before it to outline a second term domestic agenda. They point to another new ad about policies to create an "ownership society" and proposals for health savings accounts and job training as evidence. Bush's convention speech will address his domestic agenda as well.

"I don't think anybody said this would be a huge change [in message], said Matthew Dowd, chief strategist for the reelection campaign. "We're not off that track. . . . He is not not going to talk about the war on terror in his convention speech. This is a country at war. The Kerry campaign knows that. That's why they talked about it at their convention."

Advisers to Bush said the economy and national security issues will decide the Nov. 2 election and that the president is talking regularly about both. Here in Albuquerque, Bush talked about the policies he favors to support small business and help more Americans own homes and have health insurance.

Then he reminded his audience that the only way to make the economy strong is to win the war on terrorism. As he put it on here on Wednesday, "I know what I'm doing when it comes to winning this war, and I'm not going to be sending mixed signals."

The Bush campaign's new ad demonstrates emphasis on national security. "My most solemn duty is to lead our nation to protect our citizens," says the president, joined by Laura Bush.