MERIDIAN, Mississippi (Reuters) - Republican presidential candidate John McCain on Monday dismissed Democrat Barack Obama’s charge that he wants a “100-year war” in Iraq and belittled Obama’s level of national security experience.

Republican presidential candidate Senator John McCain adjusts his tie before speaking at the Los Angeles World Affairs Council March 26, 2008. REUTERS/Mario Anzuoni

McCain began a trip down memory lane, opening a tour to places where he grew from rebellious youth to war hero and politician. He was a Navy flight instructor in Meridian and the McCain airfield is named for his grandfather.

But he quickly got himself enmeshed in the politics of the day, responding to Obama’s oft-repeated charge that McCain would leave the United States in Iraq for a century.

Obama had said earlier on Monday he did not think the charge was unfair, that McCain “has not been clear about what exactly would lead him to decide it’s time to pull out.”

McCain gave the Democrats an opening on the issue by using the 100-year description to describe how long the United States might need a presence in Iraq to help maintain regional stability.

But McCain said he was talking about something similar to the decades-old U.S. military presences in Japan, South Korea and Germany.

The Arizona senator, 71, said Obama, a senator from Illinois, “hasn’t read or doesn’t understand the history of this country,” an experience-versus-youth theme likely to play out in the months leading to the November election if Obama defeats New York Sen. Hillary Clinton for the right to face McCain.

“In all due respect, he displays a fundamental misunderstanding of history, of how we maintain national security and what we need to do in the future to maintain our security. But I understand it because he has no experience or background in any of it,” McCain told reporters on his campaign flight back to Washington.

McCain also said he was surprised by an offensive in southern Iraq by Iraqi Prime Minister Nuri al-Maliki because he had gotten no word that Maliki had consulted the Americans before launching it.

He said whether the mission can be deemed productive should be known in the next day or two. McCain expressed continuing annoyance at Iran, accusing Tehran of exporting weapons to Iraq and training Iraqi Shi’ite militias.

He said he believed Iran was still seeking to acquire the means to develop a nuclear weapon, although a recent National Intelligence Estimate had suggested otherwise.

MISSED ‘MINI-SKIRT’ PHASE

McCain said his past gave him a better understanding of the future, and that this is why he had embarked on a tour of places like Meridian. But he expressed some misgivings about his rebellious nature as a youth, saying young people should not do as he did, such as smoking and drinking to excess.

“Some of my behavior was very immature,” he said.

But he said, because he was a Vietnam prisoner of war for 5-1/2 years, “I regretted that the mini-skirt phase came and went while I was away.”

McCain will visit his high school outside Washington, D.C., on Tuesday and stop at the U.S. Naval Academy in Annapolis, Maryland, where he graduated near the bottom of his class. He will also go to Florida and his home state of Arizona.

While reviewing his past, McCain came face-to-face with the present, riding on his bus in Meridian with Rachel Lee, whose son, Dustin Lee, a 20-year-old Marine raised in Stonewall, Mississippi, was killed in an explosion last year in Iraq’s al-Anbar province.

McCain, a strong supporter of the U.S. troop build-up in Iraq, told Lee that the United States honored her son’s sacrifice. McCain’s wife, Cindy, wept as the woman told what happened to her son.

“We’re without words to describe how much we appreciate it. I think we are winning the war -- we’ve had a problem here in the last few days, but hopefully the Anbar province will stay quiet -- thanks to the Marines and Army,” McCain said.

(Editing by Patricia Zengerle)