The U.S. will join its European allies in pursuing economic sanctions against the Libyan government during an emergency U.N. Security Council meeting on Friday. International pressure is mounting against Libyan ruler Muammar Qaddafi and his violent crackdown on anti-government protesters. Qaddafi is digging in in Tripoli as opposition forces, who now control the eastern half of the country, advance toward the capital, raising the specter of civil war.

The U.K. and France plan to introduce a Security Council resolution calling for an arms embargo, financial sanctions, and a probe from the International Criminal Court, though the resolution may not be adopted for a week or more. The U.S. Treasury Department, meanwhile, is considering asset freezes and travel restrictions targeted at Qaddafi's government. NATO is also convening an emergency session in Brussels to discuss humanitarian assistance and evacuations in Libya while the U.N. Human Rights Council will, for the first time, hold a session to investigate one of its members and consider kicking Libya out of the body, according to The Wall Street Journal.

The Libyan uprising is now entering its eleventh day. So why are the U.S. and its allies only weighing sanctions now? One major explanation is that these countries are still evacuating their citizens, analysts suggest. The Journal, for example, notes that U.S. diplomatic efforts were complicated on Thursday when a ferry filled with Americans couldn't leave Tripoli's port because of strong winds and turbulent seas. White House press secretary Jay Carney has also suggested on Thursday that the international community needed time to reach a consensus. In response to the charge the administration has been slow to respond to the Libyan revolt, Carney stated that when "the international community comes together and speaks with one voice, it has a powerful impact in terms of persuading a government like Libya's to do the right thing."

But will the sanctions be effective? Hussein Ibish at Foreign Policy is skeptical and calls for humanitarian intervention instead. "Economic measures," he says, "take time to make their impact felt, and they will certainly not produce, and probably won't seriously accelerate, regime change. Nor will they come quickly enough to stop Qaddafi's bloodletting of his own population." Ibish adds that economic sanctions and freezing of regime assets, will only have an effect if they're supported by countries like Russia and China. On Thursday, the Russian foreign ministry claimed that while sanctions "might work in some situations, you can hardly say that they are an effective method of international action."

In an editorial, the New York Times argues that if the types of measures the U.S. and its allies are considering against Libya prove ineffective, the international community may need to contemplate more aggressive measures like offering "temporary sanctuary for refugees and imposing the kind of no-fly zone that the United States, Britain and France used to protect Kurds in Iraq from the savagery of Saddam Hussein."