Sen. Chuck Hagel, who accompanied Sen. Barack Obama on his trip to South Asia and Iraq last week, criticized the McCain campaign for its latest television ad attacking the Democratic candidate.
The ad blasts Obama for not visiting wounded troops during his visit to Germany. Obama has said he chose to cancel a visit to a military hospital there after consultations with the Pentagon, due to concerns that such a visit might be seen as using wounded troops for political purposes.
The McCain ad, which contains footage of Obama bouncing a basketball before U.S. military personnel in Kuwait, implied that Obama was being disrespectful to troops by making "time to go to the gym" during his overseas trip while at the same time cancelling a visit with wounded troops.
"Seems the Pentagon wouldn't allow him to bring cameras," the ad insinuates.
The commercial began airing after a week of news coverage of Obama appearing with foreign leaders and speaking to cheering European crowds. The McCain campaign has suggested that Obama preferred that audience to wounded American soldiers.
"John McCain is always there for our troops," the ad said.
Obama's campaign called the new accusation "wildly inappropriate."
The Republican senator from Nebraska agreed, saying on Face The Nation that the GOP's presumptive nominee 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.'
"They're better off to focus on policy differences," he said.
"It's just not responsible to be saying things like that, again, if for no other reason than for the good of this country and the world.
"One of these two men, on January 20th of next year, is going to have to bring this country together, and the world, to deal with huge problems. I think the next president is going to inherit an inventory of challenges as big as Franklin Roosevelt inherited on March 4, 1933."
Sen. Jack Reed, D-R.I., who also accompanied Obama to Afghanistan and Iraq this week, called the ad "completely distorted."
"Senator Hagel, Senator Obama and I visited the combat support hospital in Baghdad to thank those nurses, those doctors, to see patients that were there, to bring a bit of greetings from home and profound thanks," he said. "That should be in the ad that Senator McCain is running.
"I think Senator Obama made a very wise choice [about Germany]. Any suggestion that a visit to a military hospital would be political, he made the wise choice not to go.
"But when we were in Baghdad, we made a point, at the end of a very exhausting day, to go in and see these magnificent young Americans and those doctors and nurses that give such tremendous care - without a lot of fanfare, just to say 'Thanks.'
"We went to Jalalabad to see the soldiers of the 173rd. We stopped in Basra to see our soldiers down there. We went into Anbar province to see soldiers there.
"That is a completely distorted and, I think, inappropriate advertisement."
On Sunday, McCain appeared to backtrack only a little on his attacks when he told ABC's George Stephanopolous that he was not questioning Obama's patriotism when he declared earlier this week that the Illinois senator would rather lose a war than lose an election.
He said he was merely indicating that his Democratic opponent "doesn't understand what's at stake" in Iraq.
Read the full "Face the Nation" transcript here.
By CBSNews.com producer David Morgan.