Too much or too little?
There had been deep worries at the White House that American citizens would be taken hostage in Libya. This is a moment haunted by history. Echoes of Iran informed the caution of the last few days.
But now most US nationals seem to be out, the embassy has been closed and diplomats evacuated - the rhetoric has been ramped up and concrete action announced.
New White House spokesman Jay Carney said Col Muammar Gaddafi had zero credibility with his own people and announced the US would impose unilateral sanctions.
A few hours later, President Obama signed an executive order freezing the assets of the colonel and some of his close family.
The US is also hoping other countries, particularly the EU, will join in, while seeking multilateral ones. But some regard this wish as wimpish. When they look to history, they want Serbia, not Rwanda.
Politicians, including John McCain and former, mainly Republican, officials from the left and right have written to president Obama, urging him to take tougher measures including introducing a no-fly zone over Libya, using the US Air Force to stop Col Gaddafi's jets from bombing their own people.
The White House has ruled nothing out, but President Obama may be loath to use American military might in this way. This is a testing moment for those who believe in liberal interventionism. It is also a testing moment for those who don't believe that wherever possible, the West should keep its nose out of other countries' affairs.
Defence Secretary Robert Gates, who also served under President George W Bush, has told cadets at West Point military academy any future president who send troops to a third world country, like Iraq or Afghanistan, would need his head examined. Of course, no one is advocating anything like that in Libya. But it is against that historical backdrop that this White House is agonising about doing too little or too much.