“If he turns his weapons on his own people, he runs the risk,” Mr. Lieberman, Connecticut independent, said on “Fox News Sunday.”“There is a precedent now … we’re not going to allow Assad to slaughter his own people.”

Sen. John McCain, appearing on the same program, wouldn’t go as far as his colleague in comparing the uprising in Syria with the pro-democracy movements in Libya, Tunisia and Egypt.

“Every one of these countries is different,” Mr. McCain, Arizona Republican, said.

“Let’s give moral support to these (protesters) in Syria,” he said, “but let’s not take our eye off Egypt. Egypt is the key.”

On CNN’s “State of the Union,” Sen. Carl Levin, Michigan Democrat, also stopped short of backing the possibility of another American-led military intervention, this time in Syria, where anti-government protesters are being killed by security forces.

The senator said the intervention in Libya has the support of the international community, including the Arab League.

Copyright 2011 The Associated Press