Democratic Senate Armed Services Committee Chairman Carl Levin and the panel’s top Republican, Sen. John McCain, pressed President Barack Obama on Thursday to consider “limited military options” to help rebels topple Syrian President Bashar Assad.

“We believe there are credible options at your disposal, including limited military options, that would require neither putting U.S. troops on the ground nor acting unilaterally,” McCain and Levin urged Obama in a letter.

The goal, they said, would be to work with key allies in the Middle East and Europe “to stop the killing in Syria and force Bashar al-Assad to give up power.” The means? Target Syria’s air force and support Turkey if it is prepared to set up a “safe zone inside of Syria’s northern border," they wrote—notably by deploying Patriot missile batteries to deter Assad’s air power and to protect against Scud missile attacks.

The two lawmakers urged “precision airstrikes” against Syrian aircraft, noting that the top military commander in the Middle East, Gen. James Mattis, testified last week that they could take out “a fair amount” of their targets.

“Such a mission could also include Assad’s SCUD missile batteries and would not require American or allied pilots to fly into the reach of Syria’s air defenses,” Levin and McCain said. “We urge you to work with our friends and allies, as well as regional organizations, to consider this limited option.”

And the two lawmakers pushed Obama “to provide more robust assistance directly to vetted opposition groups” in Syria—that is to say, rebels deemed by the U.S. and its allies not to be extremists.

“We believe such assistance should include tactical intelligence and increased deliveries of food and medicine, fuel, communications equipment, medical care for the wounded, and other humanitarian assistance,” the senators argued. “To this end, establishing a safe haven inside Syria would also serve the important goal of delivering humanitarian assistance more effectively.”

Levin and McCain stopped short of urging the administration to provide weapons directly to the rebels, something Obama has repeatedly rejected over the course of the bloody fighting for the past three years. Independent estimates have placed the death toll at about 70,000.

Read more from Yahoo! News