(CNSNews.com) - It was a simple question for the nation's top military and defense leaders: "Do we have the legal authority to assist a Free Syrian Army that we train against Assad? Is there a doubt about that?" Sen. Lindsey Graham (R-S.C.) asked Joint Chiefs Chairman Gen. Martin Dempsey and Defense Secretary Ashton Carter at a Senate Armed Services Committee hearing on Tuesday.
The question was met with a moment of dead silence.
Dempsey looked at Carter, who said: "I am not sure about the legalities of it, Senator, to be quite honest. I'm not--"
"Let's just put it this way," Graham cut in. "If there's any doubt about whether or not we have the legal authority to protect the troops we train against Assad, please let the committee know. You don't have to answer right now, but that's a big decision. If there's a lack of legal authority, I want to know why and what can we do to fix it."
"Appreciate it, and I'll -- I'll take that back. I appreciate that, though," Carter said.
Although President Obama repeatedly has called for regime change in Syria, he is unwilling to commit U.S. troops to that effort. He insists on a negotiated political solution.
But if the U.S. military ends up defending Syrian rebels, whom we have trained, against attacks by the Assad regime, the U.S. would find itself directly involved in the regime change effort.
Earlier in the hearing, Sen. John McCain (R-Ariz.) pressed Defense Secretary Carter on the extent of U.S. support for the Syrian rebels that the U.S. is training to fight ISIS.
"Now, you mentioned we are currently training about 60 fighters. I've got to tell you after four years, Mr. Secretary, that's not a very impressive number. And is it true that with these people that you are training and equipping to fight in Syria, is it true you are telling them they're only there to fight ISIS and not Bashar Assad? Is that true?" McCain asked.
Carter said the U.S. is "arming and training them in the first instance to go after ISIL and not the Assad regime. That's our priority. And these are people who are inclined in that direction and come from areas that have been overrun by ISIL and have that motivation."
But what if those troops are barrel-bombed by Bashar Assad? McCain asked.
"I think we have some obligations to them once they are inserted in the field," Carter replied.
McCain asked if that means the U.S. would defend the Syrian troops against barrel bombing:
"Well, that decision will be faced when we introduce fighters into the field," Carter said.
"Well, that's of small comfort to those people you're recruiting right now -- that that decision will be made later on," McCain replied. "Is that -- is that fair to these young men to say we are sending you in to fight ISIS only, and by the way, we will decide on the policy whether to defend you if you are barrel bombed?"
"They know that we will provide support to them," Carter said. "Exactly what kind of support under--"
"Does that mean you will defend them against Bashar Assad's barrel bombing? Mr. Secretary, this is not a very pleasant exchange," McCain said. "I'd like to have answers to questions. Will we tell them that we will defend them against Bashar Assad's barrel bombing?"
"I think we have an obligation to help them when we equip them," Carter repeated.
"Will we tell them that?" McCain asked.
"We have not told them that yet," Carter responded.
"You have not told them that," McCain repeated. "So you're recruiting people and not telling them that (we're) going to defend them because you haven't made the decision yet, and yet you want to train them quickly and send them in."
Later in the hearing. Sen. Tim Kaine, a Virginia Democrat, told McCain he agreed with his line of questioning:
"I think it would be absolutely foolish for us not to clarify the rules of engagement for the Syrian-trained folks inserted back into the field, to make clear that the U.S. will support them if they come under attack by the Assad regime.
"For them to go back in without a guarantee on that score would seem -- we -- we would lose all credibility if we don't provide that, and I -- I would just encourage the administration to clarify that aspect of the rules of engagement," Kaine said.
(Rep. Adam Schiff (D-Calif.), the ranking member of the House Intelligence Committee, told CNN on Tuesday that the Syrian opposition primarily wants to fight the Assad regime. "They also want to do combat with ISIS, but that's a secondary concern for them. Their primary concern is this government that's been barrel-bombing them.")
Kaine also faulted Congress for its failure to "authorize a war" eleven months after the air strikes started; and for its failure to pass a defense budget.
"Tomorrow is the 11-month anniversary of the initiation of the bombing campaign in Sinjar and Erbil (Iraq)," Kaine noted. "We've spent $3 billion. We've got 3,500 people deployed away from their families risking their lives.
And aside from a single vote in the Senate Foreign Relations Committee in December, there has not been House committee action or floor debate of any significance. There's not been any meaningful debate on the Senate floor about whether or not we should be engaged in this war, even though three quarters of the members of Congress, by my estimation, believe that there should be U.S. military action against ISIL with some differences in detail. But we don't want to have a debate and vote, because we don't want to put our names on it. We don't want to be held accountable for a vote.
"So we can criticize all we want, and I'll get into some criticisms, but bottom line, Congress is not doing either of the two things we are uniquely supposed to do: provide you a budget to win and authorize war."