Republican presidential candidate Sen. John McCain on Sunday asserted that his Democratic rival’s positions on Iraq were politically motivated.

“Sen. Obama doesn’t understand,” the Arizona senator said regarding Barack Obama’s (D-Ill.) opposition to the troop surge. “He doesn’t understand what’s at stake here, and he chose to take a political path that would have helped him get the nomination of his party.”

The GOP standard-bearer hopes that his foreign policy and military experience and support for the surge will help convince voters in November that he is the right choice to lead the country.

McCain, in an interview with ABC’s “This Week with George Stephanopoulos,” consistently hammered Obama on security-related issues and defended a remark he made earlier in which he said that the Democrat is willing to lose a war to win a political campaign.

The Arizona senator argued that, while he broke with President Bush and his party to demand that more troops should be sent to Iraq, Obama “made the decision [to oppose the surge], which was political, in order to help him get the nomination of his party.”

Sen. Chuck Hagel (R-Neb.), who went on the trip to the Middle East with Obama, criticized the attacks on the Democrat and said McCain is “treading on some very thin ground here when he impugns motives and when we start to get into, ‘You’re less patriotic than me. I’m more patriotic’.”

 McCain also criticized his rival for not visiting wounded troops during his trip to Germany this week.

“If I had been told by the Pentagon that I couldn’t visit those troops, and I was there and wanted to be there, I guarantee you there would have been a seismic event,” McCain said. “And so I believe he had the opportunity to go without the media. And I’ll let the facts speak for themselves.”

Hagel, who appeared on CBS’s “Face the Nation,” also defended Obama on the hospital issue.

“I think it would be totally inappropriate for him on a campaign trip to go to a military hospital and use those soldiers as props,” Hagel said. “So I think he probably, based on what I know, he did the right thing.”