WASHINGTON (CNN) -- Sen. John McCain and Joint Chiefs Chairman Martin Dempsey traded rhetorical jabs in a lively exchange Thursday over the scope of Dempsey's role as President Obama's chief military adviser.
While the overarching concern on McCain's part was the substance of Dempsey's advice to the president on the civil war in Syria, the debate soon became a surrogate battle over the wisdom of U.S. military assistance to Syrian rebels.
McCain wasted no time in voicing his disapproval of Dempsey's tenure, and that of his deputy, Vice Admiral Sandy Winnefeld, during a hearing before the Senate Armed Services Committee to consider their nominations for a second term in their roles.
"I must tell both witnesses at the onset I'm very concerned about the role they have played over the last two years," he said.
Specifically, McCain pushed Dempsey on whether Washington's "inaction" toward the situation in Syria is doing great harm to U.S. national security.
No sooner than Dempsey said, "Senator, as we've discussed..," McCain shot back saying, "I'd like to know an answer rather than a filibuster."
That set the tone for the discussion that was to follow.
The verbal jousting continued with Dempsey protesting the notion of U.S. inactivity on Syria, and McCain citing a rapidly deteriorating situation with the arrival of forces of Hezbollah to support the forces of Bashar al-Assad along with Russian and Iranian assistance.
During the exchange, Dempsey warned that "situations can be made worse" by the introduction of military force in certain conflicts. But McCain disagreed, telling the chairman at one point, "I know, perhaps better than you, because I've been there."
Dempsey later seemed to express frustration with McCain's portrayal of him "holding back from our use of military force" inside Syria. "I'm not saying that, general," McCain shot back.
"Senator, I am in favor of building a moderate opposition and supporting it," Dempsey said. "The question of whether to support it with direct kinetic strikes" is a decision for elected officials to make, he said, "not for the senior military leader of the nation."
As the approximate nine-minute exchange wrapped up, McCain pressed Dempsey to give his personal opinion to the committee of whether he advocated the use of military force in Syria to which Dempsey said it would be inappropriate to comment while the administration deliberates the issue.
"If it is your position that you do not provide your personal views to the committee when asked only under certain circumstances, then you have just contradicted what I have known this committee to operate under for the last 30 years," McCain said.
Later in the hearing Dempsey pledged to Sen. Carl Levin, D-Michigan, chairman of the committee, that he would provide the committee with an unclassified list of options for U.S. involvement in Syria along with the strengths and weaknesses for those options.
Apart from that, an aide to McCain told CNN the senator will put a hold on Dempsey's nomination until he receives answers to his questions on the U.S. role in Syria.