Unlike the tumultuous events in Egypt, where Obama frequently called for a transition in power away from Hosni Mubarak, Obama has largely adopted a more wait-and-see position in the case of Libya, drawing some criticism that he is being too reticent.

Obama has been consulting with allies about sanctions and avoiding the kind of hot rhetoric that might antagonize unpredictable Libyan leader Moammar Gadhafi, who has bedeviled American presidents for the past 20 years.

Part of Obama's caution is driven by the need to ensure Americans are safely out of Libya and cannot be taken hostage, a problem that may have been on the verge of being solved on Friday when a ferry carrying hundreds of Americans sailed for Malta.

But Obama also does not want to make any moves that could further rattle oil markets and contribute to what has been a steady rise in gasoline prices in the United States.

Some U.S. commentators warn pump prices could easily reach $4 or $5 a gallon in the months ahead and put a pinch on a U.S. economy still going through a fragile recovery, although administration officials play down this possibility.

"If it became an issue here and you saw gas prices really increase, then that makes it a domestic issue of great importance," said Merle Black, a political science professor at Emory University in Atlanta.

Obama for the past two years has battled Republican charges that he has not focused sufficiently on bringing down the country's stubbornly high 9 percent jobless rate, and the president is counting on an improving U.S. economy to drive his re-election bid in 2012.

That may be why he refused to budge from his economic "Winning the Future" message on a trip this week to Cleveland that took place when the crisis in Libya was reaching full boil. He gave a speech and talked at a roundtable and never addressed the situation in Libya.

CAUTION OK WITH PUBLIC?

Presidential historian Thomas Alan Schwartz of Vanderbilt University said at this point Obama appears to have the support of Americans. "In a way the caution that the president is showing is a reflection of what the public is okay with," he said.

Some Republicans would like to see a more aggressive approach by the White House against the killings of Libyan protesters, including creation of a no-fly zone. And they worry about the potential rise of Islamists in the region in a way that would threaten staunch U.S. ally Israel.

Potential Republican presidential candidate Mike Huckabee said this week he was in Israel during the Egypt crisis, when the United States made clear longtime ally Mubarak had to leave power.

The impression he got from Israeli officials was, "You don't have a friend in the United States anymore ... that at the first sign of difficulty, they'll leave you twisting in the wind," Huckabee said.

Some Democrats also have been surprised by the muted tone of the White House response. But Obama, who ran for president in 2008 on opposition to the Iraq war and trying to end that conflict and one in Afghanistan, has plenty of reasons to be wary of bogging the country down in a new military effort.

The Libyan crisis is just one part of the diplomatic puzzle that North Africa and the Middle East represent for the Obama administration, a situation that presidential scholar Stephen Hess of the Brookings Institution says is "full of too many parts moving at the same time."

Protests have toppled leaders in Tunisia and Egypt and rocked them in Yemen, Bahrain and Jordan.

While the United States would welcome Gaddafi's ouster, officials would prefer to see leaders of close oil-producing allies such as Saudi Arabia and Bahrain make democratic reforms that would allow them to remain in power.

"The Middle East is going to be a very different place than it is now, but there's no guarantee that it's going to be a more congenial place for the United States and its interests," said Ken Wainstein, who was White House homeland security director for George W. Bush.