LAS VEGAS – President Bush told veterans yesterday he was proud of his time in the Texas Air National Guard and sought to deflect questions about his Vietnam-era service by turning the subject to what he said were rival John Kerry’s equivocations on the war in Iraq.

“What’s critical is that the president of the United States speak clearly and consistently at this time of great threat in our world, and not change positions because of expediency or pressure,” Mr. Bush told his applauding audience in a speech to the National Guard Association of the United States.

Fighting back, Mr. Kerry said the president’s speech was full of distortions. “Why would we expect George Bush to level with us about Iraq? He never has,” the Democratic presidential candidate said.

Mr. Bush did not address questions that have been raised about his service three decades ago in the Guard or respond to accusations from Democrats that he used family ties to avoid the Vietnam War. Mr. Kerry, a Vietnam veteran, addresses the same group tomorrow and has directed his allies in the national Democratic Party to make an issue of Mr. Bush’s service.

“Nineteen individuals have served both in the National Guard and as president of the United States,” Mr. Bush said, “and I’m proud to be one of them.”

The president then outlined the history of America’s citizen-soldiers and touted his efforts to improve living and work conditions for today’s Guard. Then he turned to Iraq, noting as he does in almost every campaign stop that Mr. Kerry and Democratic running mate John Edwards joined most members of the Senate to give him authority in 2002 to wage war.

He said Messrs. Kerry and Edwards later voted against money for the war, not mentioning that his own administration once threatened a veto of the funding measure or that Mr. Kerry had supported one version of the bill. He noted that Mr. Kerry has both called for more money for Iraq and asserted that Mr. Bush has squandered money there that could be spent in America.

After casting his rival as indecisive, Mr. Bush said, “Our troops, our friends and our allies, and our enemies, must know where America stands and that America will stand firm. We cannot waver because our enemies will not waver.”

It is a major part of Mr. Bush’s reelection strategy to convince voters, especially those wary of his economic and Iraq policies, that he is the only candidate in the race steady enough to lead the nation at war.

Mr. Kerry said the troubles in Iraq prove that Mr. Bush is not that candidate. “George W. Bush keeps saying that things are getting better” in Iraq “even when we all know that’s just not true,” the Democrat said in a statement.

More than 200 protesters echoed those sentiments outside Mr. Bush’s speech site, including Bill Shettler, a 67-year-old retiree who carried a sign that read: “Bush is an idiot. 1,000 lives wasted.” At a news conference for a group of families opposed to the war, Al Zappala, a 64-year-old retired Defense Department employee from Philadelphia, said his son, Sergeant Sherwood Baker, was the first Pennsylvania National Guard soldier to die in action since World War II.

“Sherwood was sent to Iraq under false pretenses,” he said. “This war was brought about by lies by the administration.”

The National Guard and Reserve comprise about 40% of the American force in Iraq.

Mr. Bush holds a commanding lead over Mr. Kerry among veterans and their families. An AP-Ipsos poll last week found he was the choice of 58% of the people polled and Mr. Kerry was the choice of 38%.