"There's a precedent now that the world community has set in Libya and it's the right one," Lieberman said. "We're not going to stand by and allow this Assad to slaughter his people like his father did years ago and in doing so we're being consistent with our American values and we're also on the side of the Arab people who want a better chance for a decent life."

Sen. John McCainJohn Sidney McCainGOP rushes to cut ties to Moore GOP strategist: 'There needs to be a repudiation' of Roy Moore by Republicans World leaders reach agreement on trade deal without United States: report MORE (R-Ariz.) said the U.S. should give its moral support to the Syrian protestors risking their lives against a "brutal regime" but emphasized that each of the Middle Eastern nations currently experiencing conflict is unique.

McCain said he was confident Egypt and Tunisia can transition to democracy but was less clear about Yemen, which is also experiencing a backlash against the ruling leadership. He said the Arab nation is different because it is basically a tribal society cobbled into a nation by the British.

"It's going to be very difficult in some of these countries. Frankly, I have to be honest, I don't know what we do exactly about Yemen except obviously the president has to step down as he has agreed to do so," McCain said.

"Egypt is the key. Do not take our attention of of Egypt, it is the center of the Arab world."