A United Nations observer force in Syria to help monitor the nation's negotiated cease-fire was welcomed by yet another Syrian army bombardment of the city of Homs.
Now, lawmakers are concerned it may take more than talks to end the battle between Syrian forces and the opposition.
The scene has been repeated several times in the past year: Syrian tanks firing on the city of Homs.
According to United Nations reports, more than 10,000 people have now died in Syria's nationwide uprising and the crackdown on anti-government protestors by President Bashar Assad.
Sen. John McCain, R-Ariz., and others say it's past time for the United States and its allies to help stop the slaughter -- without sending U.S. troops.
"[Sen.] Lindsey Graham and [Sen.] Joe Lieberman and I have said continuously, no boots on the ground, no unilateral action," McCain told CBS' "Face the Nation."
"But to sit by and watch this wanton massacre is a betrayal of everything we stand for and believe in," he added.
The U.N. Security Council continues to send envoys and pass watered-down resolutions for cease-fires that don't last. The latest resolution calls for a couple dozen U.N. observer forces to monitor the violence. The first six arrived on April 15.
"It is very important that the cessation of violence must continue and the Syrian authorities must exercise maximum restraint. And again, the opposition forces also should fully cooperate so this cessation of violence will continue," U.N. Secretary General Ban Ki-Moon said.
McCain believes Assad has no intention of complying with U.N resolutions.
"We need to get a sanctuary for the free Syrian army. We need to get them supplies. We need to get them weapons," he urged. "And there are many ways to get weapons to them."
"We showed that in Libya. We showed that in Afghanistan and many other times," McCain continued. "It's not a fair fight."
The U.N. plans to increase the observer team to 30 people, all of them unarmed.