SAPPORO, Japan - LeBron James and Dwayne Wade had a front-row seat for basketball history and hated every minute of watching it.

US forward LeBron James passes a ball during the official training session of the Group D preliminary round of the World Basketball Championship in Sapporo. USA Basketball insisted on three-year commitments from 24 men who will be the core not only of the World Championship team but the 2008 Beijing Olympic team.[AFP]

Two years ago, the young National Basketball Association stars spent much of their time on the bench as the United States struggled to a bronze medal at the Athens Olympics, losing three games and any remaining aura of invincibility.

"We didn't understand how big the Olympics were and it showed," James said.

"As a team, we didn't know what to expect. We just thought we would go out there and win."

While Allen Iverson and Stephon Marbury struggled, US coach Larry Brown left out James and Wade much of the time in favor of more experienced NBA talent.

"It was frustrating when your team is not doing good and you can't help," James said. "We never had time to come together as a team. I was out of the loop and I wasn't the only one."

The first Olympic defeats by a US collection of NBA talent prompted a change in philosophy, a new team-oriented style symbolized by new coach Mike Krzyzewski, a US legend at collegiate dynasty Duke University.

USA Basketball insisted on three-year commitments from 24 men who will be the core not only of the World Championship team here but the 2008 Beijing Olympic team.

"This group is charged with restoring American basketball to its proper place," US coach Mike Krzyzewski said.

"For some reason, the world thinks it has cast its spell on American basketball by saying Americans can't play against a zone, share the ball and commit to a team. We'll see. This group needs to shatter all those notions.

"Just play great basketball. Then nobody will be able to say anything."

Since Athens, James has matured into a team-oriented playmaker who has lifted the Cleveland Cavaliers from NBA doormat to serious contender and Wade has joined with Shaquille O'Neal to bring the Miami Heat an NBA title in June.

"If there is one guy who everyone looks up to, because of his most recent accomplishment, it's Dwyane Wade," Krzyzewski said. "He defines leadership by example."

He found Athens a humbling experience as well, one that inspires him for a better result now and in Beijing.

"It's embarrassing when we get out there with a bunch of different guys and it seemed like we didn't get along," Wade said.

While the Americans were able to score at will during most of a 5-0 warm-up tour before the World Championships, Krzyzewski has stressed defence as the most crucial aspect of coming together as a championship team.

"You can't always make a shot but you can play hard, defend and rebound every second of every game," Krzyzewski said. "Defense unifies and gets you aggressive and creates scoring opportunities."

There is some extra motivation for Team USA to capture the title as the world champion receives an automatic berth for the 2008 Beijing Olympics.

Unless they claim the crown, the Americans will have to qualify at next year's Tournament of the Americas in Venezuela.