BEIRUT — It has been 18 months since the streets of Arab cities erupted with rage against their rulers, launching the Middle East on a roller-coaster ride of hope and despair, victories and defeats.

Perhaps none of the many turning points has been quite as profound as the understated ceremony in Cairo on Saturday at which a bearded and bespectacled former political prisoner was sworn in as the first democratically elected president of the Arab world’s most populous country.

Mohamed Morsi’s ascent was the culmination of a far longer journey, the 84-year quest for power by the once-outlawed Muslim Brotherhood. And whatever the constraints on his authority or the challenges that lie ahead, the significance of the moment for a Middle East still struggling to find its way amid the tumult unleashed by the Arab Spring was lost on few.

“This is a watershed, not only in Egyptian politics but for the politics of the entire region,” said Hilal Khashan, professor of political science at the American University of Beirut. “Egypt is the trendsetter, the base of the Arab world, and developments in Egypt are likely to affect the whole Arab world.”

For some, it was a cause for celebration, for others, deep unease.

The euphoria that accompanied the toppling of autocratic leaders in Tunisia, Egypt and Libya last year has long since been tempered by the harsh realities of repression in Bahrain and bloodshed in Syria, where the 15-month-old rebellion against President Bashar al-Assad’s rule appears to be descending into a full-blown civil war.

From the countries of the Persian Gulf to Jordan, Iraq and Lebanon, many secularists and religious minorities are also watching with dismay the wave of religiosity washing across North Africa, with Islamists poised to do well in Libya’s first democratic elections this month and already running the government in Tunisia.

Though Morsi has resigned from the Brotherhood in a gesture of national unity, the installation in Egypt of a president who ran on a Brotherhood ticket seemed only to project the trend deeper into the heart of the Arab world, in ways that both inspired and alarmed.

“There is a high level of worry, suspicion and euphoria,” said Labib Kamhawi, a political analyst in the Jordanian capital, Amman. “It all depends on where you stand on the political spectrum.”

The effect in Syria

Nowhere is the impact likely to be more deeply felt than in Syria, where the Syrian branch of the Brotherhood is emerging as a key player in the political opposition to Assad and as a source of contention, illustrating the complex divide playing out across the region between Islamists and secularists, the rulers and the ruled.

At a school outside the Syrian city of Hama now used by activists as a media center, half a dozen Free Syrian Army fighters watched Morsi’s inaugural speech broadcast live on TV from Cairo University. When he pledged to “spare no effort” to support the Syrian revolutionaries in their struggle against Assad, they burst into applause and cries of “God be with you!” said Musab al-Hamadee, an activist who was present and relayed the fighters’ reactions to the speech over Skype.

“This convinces us that all revolutions will succeed,” he said. “We are more optimistic now.”

The comment was an unusually direct foray into foreign policy for Morsi, and it pointed to the ways in which the Brotherhood’s ascent in Egypt may help empower its affiliates elsewhere in the region.

Members of the Syrian Muslim Brotherhood are planning to meet with Morsi in Cairo soon to explore how Egypt can help the Syrian effort to overthrow Assad, said Molham al-Drobi, a senior figure in the Syrian movement. A key request will be for Egypt to prevent passage through the Suez Canal for Russian and Iranian ships supplying weapons to the Syrian government, a move with potentially significant geopolitical implications.

“It makes me feel proud, and I am also feeling the challenge the Muslim Brotherhood is facing to prove to the world that the Muslim Brotherhood is capable of running countries,” Drobi said of Morsi’s victory. “This will prove not only to Arabs, but the whole globe, that the Muslim Brotherhood is a threat to nobody.”

Yet some Syrian activists expressed misgivings.

“The secular forces in the revolution, of which there are many, see that the Brotherhood is trying to push its agenda on the backs of the revolutionaries, so there is this negative reaction,” said Shakeeb al- Jabri, who is based in Beirut.

Concerns of critics

Members of Syrian minorities, including Christians, Alawites and Kurds, share similar concerns, said Emile Hokayem of the International Institute for Strategic Studies, who is based in Bahrain. So, too, do the region’s monarchs, who have successfully held off secularist demands for reform with their appeals to traditional values.

“Now we have the emergence of an Islamic movement that knows how to merge Islamic ideals with a republican system, and this could be a competing model,” Hokayem said. “There are particular concerns about what a Muslim Brotherhood foreign policy might look like. Will it be a movement that tries to export its model? That would be very disruptive.”

Morsi seemed to address those concerns directly Saturday, telling the audience at Cairo University that “Egyptians do not export revolutions.”

Egypt is still a long way from being in a position to regain its long- squandered role as the region’s dominant power, analysts say.

With the country consumed by domestic politics and the challenges of its faltering economy, “Cairo will continue to be the non-player . . . that it has been for quite some time,” Robert Satloff of the Washington Institute for Near East Policy wrote last week.

“But the potent imagery of Brotherhood victory is likely to transcend that gritty reality,” he added. “The shockwaves will be felt across the Middle East.” (© 2010 The Washington Post Company 07/01/12)