Defense Secretary Chuck Hagel warned a Senate panel that intervening in Syria's grinding, brutal civil war risked plunging the U.S. into another bloody conflict. Even as Hagel did so, however, he announced a contingent of soldiers have deployed to neighboring Jordan as a hedge.

"We have an obligation and responsibility to think through the consequences of any direct U.S. military action in Syria," Hagel told the Senate Armed Services Committee this afternoon. "A military intervention could have the unintended consequence of bringing the United States into a broader regional conflict or proxy war."

Yet Hagel said that to prevent spillover violence, last week he ordered an "Army headquarters element" to go to Jordan to help coordinate contingency planning, particularly over a potential chemical-weapons attack. CNN reports that up to 200 soldiers from the 1st Armored Division at Fort Bliss, Tex. will form a potential "joint task force for military operations."

There's been some political momentum in recent weeks in Washington toward deepening U.S. involvement in Syria, which is currently limited to non-lethal aid. The panel's chairman, Sen. Carl Levin (D-Mich.), an Obama administration ally, last month called on the U.S. Air Force to set up a no-fly zone against dictator Bashar Assad. The administration, hesitant of getting sucked into a new war while it winds down the Afghanistan one, has begun providing food and medical supplies to the armed Syrian opposition directly – displeasing the Syrian rebels – while deliberating additional steps.

Hagel didn't rule out intervention, and called the civilian massacres "tragic." But he said it was an "option of last resort." Rather than alleviate the slaughter of Syrian civilians, it could "hinder humanitarian relief operations" and "strain other key international partnerships," likely a reference to Russia, an Assad ally. The Syrian opposition is fragmentary and unreliable. And Hagel reminded senators that getting into a Syrian war is easier than getting out of what could be "a significant, lengthy, and uncertain military commitment."

With the departure of Marine Gen. James Mattis, the former top U.S. military commander in the Middle East, there is little appetite among top defense officials to take direct action in Syria. Before his recent retirement, Mattis told the same Senate panel he had a plan to "disrupt" Syrian chemical weapons. But Pentagon officers more typically cite the need for a massive ground force to provide an assurance that Assad's chemical arsenal is secure, which is frequently interpreted as a signal of reluctance.

Hagel has tended to sound such cautions. During his January confirmation hearings, he warned against getting involved in France's war against Malian Islamist militias. A Vietnam veteran infantryman, Hagel's standard Pentagon speeches often include a line about military interventions being "worthy of the service, sacrifice and loyalty" of U.S. troops.

"I'm not sure there's another issue where thousands of people are pouring into refugee camps and are being slaughtered as we speak," said Sen. John McCain (R-Ariz.), perhaps the Senate's leading advocate of taking military action in Syria. "This is a humanitarian issue that's simply unacceptable to continue on the path that it's on."