Human rights activists estimate that Syrian President Bashar Assad’s force have killed more than 400 protesters as tanks roar through city streets while U.S. President Barack Obama remains relatively silent.

American observers are asking out loud why the voice of Obama President Obama, who turned his back on Mubarak, is barely heard as Assad’s tanks shoot at civilians in Daraa and surround Banias.

“It's not yet clear if America wants President Assad to step down,” reported ABC’s Meredith Griffiths. An eyewitness told her that Syrian soldiers and police “won't even let you get first aid to them and the ambulances; they're being shot at by security police.”

The Obama administration, which last month called Assad a "reformer” and has tried to “engage” Syria away from Iran, has said only, “We continue to look for ways and are pursuing a range of possible policy options, including targeted sanctions, to respond to the crackdown in Syria.” However, American sanctions on Syria already have been in place for several years.

President Obama has relied on rhetoric, after weeks of relative silence. On Friday, Obamas said that “The United States has repeatedly encouraged President Assad and the Syrian government to implement meaningful reforms, but they refuse to respect the rights of the Syrian people or be responsive to their aspirations."

“As the casualties mount, liberals in America are wondering where their champion of human rights, President Obama, has disappeared to,”wrote Stephen Brown for FrontPage Magazine. “He was front and center in the Egyptian crisis, and even sent American warplanes to bomb the murderous dictatorship in Libya. But so far in Syria, Obama has only condemned the violence in conjunction with other world leaders, calling the Assad regime’s actions ‘“outrageous.’

“But why such a milquetoast response to the client regime of the Islamic Republic of Iran, a world sponsor of terror? Why are Egyptian allies (Mubarak) and Libyan gadflies (Qaddafi) treated more aggressively, and more swiftly than a regime, whose fall might actually benefit American interests?

Even the Washington Post, normally friendly to the president but increasingly critical of his Middle East policy tactics, editorialized, “As a moral matter, the stance of the United States is shameful. To stand by passively while hundreds of people seeking freedom are gunned down by their government makes a mockery of the U.S. commitment to human rights.”

The American government may be trying not to upset the already turbulent Muslim Middle East by provoking Iran, Syrian’s key ally, but if the Syrian uprising follows the fortunes of those in Egypt, Yemen and Tunisia, “the president’s unintelligible policy regarding the Middle East will…leave an indelible mar on his presidency,” Brown wrote.