"The greatest humanitarian crisis in the world is unfolding in and around Syria," said Sen. Robert Menendez (D., N.J.), the committee chief. ". . . The United States must play a role in tipping the scales toward opposition groups and working to build a free and democratic Syria."
Sen. Bob Corker of Tennessee, the panel's top Republican, implicitly criticized the Obama administration as he joined Menendez in embracing the measure. "Much of the policy on Syria has been done on an ad hoc basis," Corker said.
Opposing the legislation were Sens. Rand Paul (R., Ky.), a potential presidential candidate, and Democratic Sens. Tom Udall of New Mexico and Chris Murphy of Connecticut.
"It's impossible to know who are friends are," Paul said. His arguments put him at odds with another potential White House candidate - Republican Sen. Marco Rubio of Florida, who backed the legislation.
Meanwhile, despite recent rebel setbacks in Syria's civil war, the main opposition bloc signaled a tough line Tuesday on attending possible peace talks with Assad's regime.
Two senior members of the Syrian National Coalition said the group first wants ironclad guarantees of Assad's departure as part of any transition deal and more weapons for rebel fighters. The group's final position is to be hashed out in a three-day meeting of its General Assembly in Istanbul, Turkey, this week.
Tuesday's comments highlighted the wide gaps between many in the Syrian opposition and the regime just weeks before the United States and Russia hope to bring the sides together.