(CNN) - In the world of politics, it used to be a hard-and-fast rule: "Politics ends at the water's edge" - the old Washington practice that when politicians used to travel abroad, their political opponents often refrained from criticism, at least with regards to foreign policy.
But as Barack Obama continues his trip throughout the Middle East, John McCain sharply criticized the Illinois senator Monday morning over his initial opposition to the surge policy in Iraq and his short resume in dealing with foreign affairs.
Watch: Obama, al-Maliki meet
But McCain aides told CNN last week they consider the trip chiefly political in nature - an attempt by Obama to burnish his foreign policy credentials - and said both his campaign and the Democratic National Committee shattered precedent by attacking McCain while he was in Europe and the Middle East in March, and during his recent trips to Canada, Colombia and Mexico.
Listen: McCain camp on the offense
"Sen. Obama has said this is going to be a listening tour. We certainly hope very sincerely he listens to the advice of our military commanders," McCain senior foreign policy adviser cheunemann said in a campaign conference call Monday morning. "The question is whether he will listen to them. Or will he ignore their military judgment on the importance on having a conditions based withdrawal and supplant it with his own military assessment which is really based on a political calculation rather than any experience he has."
Those comments echoed the remarks of McCain earlier Monday.
"We are winning the war and Sen. Obama was wrong," McCain told CBS. "He railed against it. He voted against the surge and he said it would fail. He was wrong there, and there's very little doubt in my mind that he will see for himself that he had a gross misjudgment and he will correct that."
McCain made similar comments in an interview on ABC, taking subtle jabs at Obama for failing to meet with the top U.S. general in Iraq, David Petraeus, until now.
"I'm glad that Senator Obama's going to get a chance for the first time to sit down with General David Petraeus and understand what the surge was all about, why it succeeded and why we are winning the war,” said the presumptive Republican nominee. “And that is because we carried out a strategy which has succeeded, and Sen. Obama rallied against, voted against, and used his opposition to the surge as a way of gaining the nomination of his party."
McCain also criticized Obama for not doing more as chairman of a Senate Foreign Relations Subcommittee to deal with NATO's involvement in Afghanistan. Since assuming that chairmanship two years ago, Obama has yet to hold a hearing dealing with the ongoing war in that country - though Sen. Joe Biden, the chairman of the full committee, said last week those issues are dealt with at the full committee level, not Obama's subcommittee.
In the network interviews, McCain also took jabs at Obama over his proposals to battle the county's economic woes, and defended his own experience on the issue.
"I have far more experience on the economy than Senator Obama," he said on NBC. "I'm very strong on the economy. I was chairman of the Senate Commerce Committee on Science and Transportation, which addresses all these issues."