WASHINGTON » As the Obama administration confronts the spectacle of angry protesters and baton-wielding riot police officers from Tunisia to Egypt to Lebanon, it is groping for a plan to deal with an always-vexing region now suddenly spinning in dangerous directions.

In Egypt, where a staunch ally, President Hosni Mubarak, faced the fiercest protests in years Tuesday, and Lebanon, where a Hezbollah-backed government is taking shape, the administration is grappling with volatile, potentially hostile forces that have already realigned the region’s political landscape.

These were surprising turns. But even the administration’s signature project in the region — Israeli-Palestinian peace negotiations — became even more intractable this week, with the publication of confidential documents detailing Palestinian concessions offered in talks with Israel. The disclosure makes it less likely that the Palestinians will agree to any further concessions.

In interviews in recent days, officials acknowledged that the United States had limited influence over many actors in the region, and that the upheaval in Egypt, in particular, could scramble its foreign-policy agenda.

So it is proceeding gingerly, balancing the democratic aspirations of young Arabs with cold-eyed strategic and commercial interests. That sometimes involves supporting autocratic and unpopular government — which has turned many of those young people against the United States.

President Barack Obama called Mubarak last week, after the uprising in Tunisia, to offer reassurance. But Tuesday, the White House warned Hezbollah against coercion and intimidation, and officials said the United States might go as far as pulling hundreds of millions of dollars of aid from Lebanon. The administration sent a senior diplomat, Jeffrey D. Feltman, to Tunisia to express support for pro-democracy forces as they prepared for elections after the ouster of President Zine El Abidine Ben Ali.

"We aren’t meddling," Feltman said in a telephone interview from the capital, Tunis. "We’re trying to play a supportive role. It’s a question of us, if asked, being able to provide appropriate assistance."

While there are important differences between North Africa and Lebanon, the two situations pose similar challenges.

Some analysts argue that the United States should seize on Tunisia to advance democracy across the Middle East — reprising the "freedom agenda" of the Bush administration and providing Obama a rare opportunity to deliver on pledges to build bridges to the Muslim world.

Secretary of State Hillary Rodham Clinton came closest to doing that in Qatar two weeks ago, when she criticized Arab leaders for their autocratic ways, a mere 24 hours before Ben Ali was driven from office. But Clinton’s speech does not augur a return to the Bush approach, officials said.

For one thing, clamoring for democracy did not work so well for President George W. Bush, administration officials said. More important, a wave of upheaval could uproot valuable allies — not just Mubarak but President Ali Abdullah Saleh of Yemen, who is helping the Pentagon with counterterrorism operations and is also facing protests.

An uprising in Tunisia, a peripheral player in the region, is not the same as an uprising in Egypt, a linchpin. The Egyptian government is a crucial ally to Washington, but the population is very suspicious of U.S. motives, and the potential for Islamic extremism lurks.

"These countries are going to go at a different pace," said Daniel B. Shapiro, a senior Middle East adviser on the National Security Council. "One couldn’t, or shouldn’t try, to come up with a cookie-cutter ideal of how to approach it."

The administration has sought to balance its reassurance of Mubarak with expressions of concern about rigged elections and jailed dissidents in his country. But it may find it harder to avoid singling him out if the crowds keep building in Cairo.

"The challenge for the administration is to find the right balance between identifying the U.S. too closely with these changes, and thereby undermining them; and not finding ways to nurture them enough," said Aaron David Miller, a public policy fellow at the Woodrow Wilson International Center for Scholars. "They don’t yet know how to do that."

Some critics say the administration erred by putting the peace process at the center of its strategy for the region, overlooking a restive Arab population.

"They put U.S.-Egyptian relations within the prism of the Israeli-Palestinian conflict," said Elliott Abrams, a Middle East adviser in the Bush administration. "But what happens in Egypt originates in Egypt."

Obama came into office determined to play down the Bush administration’s Iraq-centered "freedom agenda," the very public push for democratic change. In his speech to the Islamic world in Cairo in June 2009, Obama said each country should chart its own path to democracy and rejected military intervention as a way to accelerate the process.

Instead, the administration has worked with pro-democracy groups to advocate for freer media and assembly. It has pushed for outside monitors to scrutinize elections in Jordan and Egypt. And it has encouraged social networks like Twitter and Facebook to spread the word about pro-democracy movements — the very networks that helped spread word of demonstrations in Tunisia and Egypt.

"In giving us guidance as we develop our policies in the region, the president was adamant that we take stock of the brittleness and hidden risks of the status quo," said Samantha Power, a senior director at the National Security Council who handles human rights issues.

But critics say bottom-up efforts have failed to open up political space in Arab countries. Despite the push for monitors in Egypt, its recent parliamentary elections were judged to be far less honest than the previous elections, in 2005.

Steven Heydemann, a vice president at the United States Institute of Peace, argued in a blog this week that the time had come for the United States to confront Arab leaders more forcefully, demanding that they repeal emergency laws and scrap state security courts, which they use to exercise arbitrary power.

Administration officials said they pressed Mubarak repeatedly not to reinstate Egypt’s emergency law, which has been in place since 1981. He did so anyway, but officials said he released virtually all the political prisoners that were on a list compiled by Human Rights Watch. In his call with Mubarak, Obama also linked the bombing of a Coptic Christian church to the rights of religious minorities.

Still, critics say the pressure has been mostly in private, which does little to build support among impatient young Arabs. In Qatar, Abrams said, Clinton did not call as forcefully for human rights as she did a day later in a speech about China.

For some analysts, the big question is whether the administration should seize on Tunisia as a lever to push for change elsewhere.

"If Tunisia works out, that could be much more of an inspiration to Arab countries than Iraq ever was," said Steven A. Cook, a senior fellow for Middle East studies at the Council on Foreign Relations. "It is an unexpected windfall. That’s why they should be making the most of it."