The violence across the heartland of the Arab Spring reaches far beyond the cries of anger against America and deep into one of the region's most high-stakes showdowns: ultraconservative Islamists seeking to challenge the new leadership struggling for stability in places such as Egypt and Libya.

Islamic absolutist factions such as Salafis have been largely kept on the political margins as more pragmatic Islamist groups — including the Muslim Brotherhood of Egypt's President Mohammed Morsi and the Ennahda party in Tunisia — rose to power from the wreckage of pro-Western regimes.

But the hard-liners have never been counted out.

In eastern Libya, attackers armed with machine guns and rocket-propelled grenades fought under the black flag of the ultraconservative faction Ansar al-Shariah in Tuesday's assault on the U.S. consulate in Benghazi that left the U.S. ambassador and three other Americans dead.

In Egypt's Sinai peninsula, Bedouin-style Islamic hit squads, believed inspired by al-Qaida, have forced Morsi to deploy tanks and post extra guards along the strategic Suez Canal.

This week's mayhem, including protesters breaching the walls of the U.S. Embassy in Yemen on Thursday, appears to be an opportunity seized by groups such as the Salafis, which follow an austere brand of Islam that has provided some of the dogmatic underpinnings for al-Qaida and other jihadi factions.

The rallying cries for the assaults on the U.S. diplomatic sites — which began on the 11th anniversary of the 9/11 attacks — were the now-infamous YouTube clips of an obscure movie called "Innocence of Muslims" that denigrated Islam's Prophet Muhammad.

But they are unlike the reactions to other perceived offenses against Islam that touched off protests across the Muslim world, such as the outrage to a Danish cartoon of Prophet Muhammad in 2005. The core of the current violence has remained within the Arab Spring countries where hardline Islamists are trying to exert their clout after decades of repression under rulers such as Egypt's Hosni Mubarak, who saw the Salafis and others as direct challenges to the state.

Now, it's Morsi and other new Arab Spring leaders who must find a way to cope with the pressures.

The attacks on U.S. diplomatic sites "should not be seen in isolation, but are part of a broader list of challenges to the state," said Mustafa Alani, an analyst at the Geneva-based Gulf Research Center. "The question is one of capability ... to establish their legitimacy as strong governments?"

For the West, it becomes a critical narrative for the next chapters of the Arab Spring. A rise in hardline Islamist influence brings an array of major complications for Washington and its allies. They include the stability of the elected governments in Cairo and Tunis, and whether Libya could follow Yemen as a foothold for al-Qaida-inspired militants.

Then there is the question of Syria, where the rebels are strongly backed by Saudi Arabia and other Gulf nations that favor conservative Islam.

Richard Murphy, a former U.S. ambassador to Saudi Arabia and former assistant secretary of state for the Near East and South Asia, said the current show of force by the Salafis and others could add to the "already extreme caution" by Washington policy makers over how to deal with Syria's possible collapse into dozens of rival factions if President Bashar Assad falls.

"What we've seen over the past days shows the currents that have been there all along, but were kept bottled up by the regimes like Mubarak," said Murphy. "The Arab Spring let it all out and it's still unclear where it will all lead."

At the same time, the Gulf states including Saudi Arabia are frightened over a possible expansion of the Muslim Brotherhood — ironically inspired by the Arab Spring — that could challenge the region's ruling families.

At a small rally in Kuwait City, protesters chanted: "Obama we are all Osama."

Libya remains one of the huge wild cards. Benghazi and the eastern region — once the center of the uprising against Moammar Gadhafi — is now seen as potential fertile ground for Islamic radical groups such as Ansar al-Shariah. The elements are there: weak central authority and many weapons left over from the rebellion.

The leader of Ansar al-Shariah, Youssef Johani, denied any involvement in the Benghazi attack — even though his group's black flag was carried by the assailants.

The firepower and apparent military-style coordination used against the Benghazi consulate has raised speculation that it was not a spontaneous attack and could have been timed for the Sept. 11 anniversary.

Ehsan Ahrari, a Virginia-based political analyst and commentator, sees a bigger quandary for Washington, though. It's framed as the traditional hearts-and-minds puzzle: how to build ties with the new Arab Spring leaders while trying to reach out to people suspicious of the U.S. role in the region.

A 26-year-old protester outside the U.S. Embassy in Cairo showed how difficult that can be. Gomaa Abdel-Rahman Kajo backed Morsi's Salafist opponent, Hazem Abou-Ismail, who was bumped from the presidential race because his mother is American, which violated rules about any foreign ties for holders of Egypt's top office.

Kajo said Morsi "won't be able to rein in" protesters unless he clearly rebukes America over the film.

"American views us as slaves, and they are the masters," said Kajo. "We are telling them: We are the masters and they are slaves."

Morsi appeared to stumble with the crisis. Only two weeks ago, he emerged as a hero in the West and Arab world after going to Tehran and blasting the Iranians for their support of Assad. After the embassy assault, however, he left the U.S. hanging by not immediately condemning the attack and only issuing a bland statement on Facebook a day later pledging to protect diplomatic sites.

In an apparent bid to ease the sting with Washington — and avoid derailing a proposed $1 billion debt relief package — Morsi on Thursday condemned the movie for "provocations" against Islam but said it "cannot be taken as a justification for attacking embassies or consulates."

"If there's one big lesson from the Arab Spring, it's that the Islamists feel it's their turn after facing repression for decades," said Sami al-Faraj, director of the Kuwait Center for Strategic Studies. "Now comes the struggles for power and policy between moderates and extremists."


Murphy is the bureau chief in Dubai and covers Middle Eastern affairs.


Associated Press writers Hamza Hendawi and Sarah El Deeb in Cairo, and Adam Schreck in Dubai, United Arab Emirates, contributed to this report.