Egypt's President Mohamed Morsi, right, and Foreign Minister Mohamed Kamel Amr, left, meet with Sudan's Foreign Minister Ali Ahmed Karti at the presidential palace in Cairo on Aug. 25. (Amr Abdallah Dalsh/Reuters)

For decades, the Muslim Brotherhood was forced to operate in Egypt’s shadows. Now its leaders, closely allied with President Mohamed Morsi, are quickly finding that opposition tactics don’t always work when they are in charge.

In the latest example of that, the Brotherhood’s calls last week for demonstrations against an anti-Islam YouTube video drew an unhappy phone call from President Obama and led to a halt in aid negotiations crucial to the Egyptian economy.

Top Brotherhood officials say they are maturing as they grow into their new role as Egypt’s dominant political power under Morsi, a former head of the group’s political wing. But they say they also find themselves caught between the moderating force of office and a sharp tug toward religious and social conservatism from Islamist groups that sparked the protests at the U.S. Embassy here.

A top Morsi adviser, Essam el-Erian, said this week that the newness of democracy in Egypt has compounded the challenges the group faces in a country ruled by autocratic military leaders since the toppling of the monarchy in 1952.

“In any democratic country, you have a rotation of power,” said Erian, the interim chairman of the Brotherhood’s political wing. But in Egypt, he said, those who are now politicians have spent 60 years in the opposition.

Failure to find the right balance could lead to a split between moderate and conservative forces in a nation of 83 million whose long-term success is critical to the Arab world, officials and analysts say.

“It’s going to be very difficult to find a way forward and keep it all together,” said Elijah Zarwan, a Cairo-based expert on Egyptian politics at the European Council on Foreign Relations. Morsi “is really walking a very delicate tightrope.”

The Muslim Brotherhood, a moderate Islamist group, has said that it wants an expanded role for religion in Egyptian life but has tried to be inclusive in the 19 months since massive protests forced Hosni Mubarak to step down after decades in power. The movement was founded in 1928 and was banned and repressed almost continuously until Mubarak’s departure, drawing popular support by providing social services to some of Egyptian society’s most vulnerable in a country with sharp divides between rich and poor.

The revolution transformed the Brotherhood’s status overnight. Leaders, some of whom had been imprisoned for years, suddenly became the heads of the biggest, best-organized civil group in the country. They have slowly ramped up their engagement in political life, first capturing nearly half the seats in parliament and then winning the presidency after first saying they would limit their parliamentary presence and skip the presidency altogether.

Now leaders say they will contest every single parliamentary seat if elections are held again after the legislature was dissolved over the summer.

“The people are in a hurry for democracy,” Erian said.

Morsi further cemented his power in mid-August when he dismissed some of the military’s top leaders, enshrining civilian control over an army that has long dominated Egyptian political life. In a move toward inclusiveness, he appointed a cabinet made up mainly of technocrats, with a few Muslim Brotherhood affiliates in key positions.

But with leadership come new responsibilities, and the Brotherhood has been evolving quickly, sometimes by the day.

Last week, it was the ultraconservative Salafist Nour party, a rival to the Brotherhood, that took the lead in calling for
protests against the anti-Islam video. The demonstrations at
the fortress-like U.S. Embassy helped spark a week of anger toward U.S. targets across the region — and it also put pressure on Morsi and his circle.

“They were basically forced to choose between the Islamists and the United States,” said Michele Dunne, a former Middle East specialist at the National Security Council who is now at the Atlantic Council. “Their initial response was to try to outflank the Salafis to show that they, the Brotherhood, were the real defenders of Islam.”

After protesters stormed the embassy on Sept. 11, breaching the compound and pulling down and destroying an American flag, Morsi waited 24 hours, then posted a mild condemnation on Facebook. The political wing of the Muslim Brotherhood, meanwhile, called for more demonstrations against the YouTube video.

Protesting is “both the right and the duty of all Egyptian people,” it said in a statement on Thursday of last week.

Only after Obama’s stern phone call did Morsi get tough on the protests, tempering the calls for a massive nationwide turnout and, on Saturday, cracking down on the hundreds of people who remained in Tahrir Square, 350 yards from the embassy. Tahrir has been swept clean, and government workers are putting in plants in place of permanent encampments.

Brotherhood officials say they are learning.

Gehad el-Haddad, a senior adviser to the Brotherhood, said the Freedom and Justice Party, the Brotherhood’s political wing, “is a new party, less than two years old, and the Muslim Brotherhood has a very new role that they have not been accustomed to after many years of being underground.”

Whether the new moderation will work in the long term is another question. Before parliament was dissolved, ultraconservative Islamists held about a quarter of the seats, making them the second-largest bloc in the legislature. The more compromises the Brotherhood has to make, some analysts say, the harder it will be to retain its current level of support.

And if leaders don’t succeed in addressing Egypt’s crippling poverty and unemployment, they also risk losing broad-based support. For now, aid and investment will have to come from outside Egypt — the country’s $10 billion funding gap and dwindling foreign currency reserves are too hard to handle alone. Many Brotherhood officials sound above all like hard-nosed business people.

“We’re working with the American community,” Hassan Malek, a top Muslim Brotherhood businessman who advises Morsi on international investment, said in an interview shortly before the protests last week. “We’ve decided to be exposed to the whole world because we really need investment.”

For now, the Brotherhood has quieted the protests. Even the Nour party has issued conciliatory statements condemning the violence outside the embassy. But leaders say they will need to remain vigilant to hold their disparate wings together.

Across the Arab world, Erian said, newly democratic countries are facing “enormous and difficult challenges’’ and need to work to ensure that “society does not split up into sects or factions.”

Ingy Hassieb contributed to this report.