CAIRO -- Sheik Mohamed Abu Sidra had watched in exasperation for months as President Mohamed Morsi and the Egyptian Muslim Brotherhood bounced from one debilitating political battle to another.
"The Brotherhood went too fast, they tried to take too much," Sheik Abu Sidra, an influential ultraconservative Islamist in Benghazi, Libya, said Thursday, a day after the Egyptian military deposed and detained Mr. Morsi and began arresting his Brotherhood allies.
But at the same time, Sheik Abu Sidra said, Mr. Morsi's overthrow had made it far more difficult for him to persuade Benghazi's Islamist militias to put down their weapons and trust in democracy.
"Do you think I can sell that to the people anymore?" he asked. "I have been saying all along, 'If you want to build Shariah law, come to elections.' Now they will just say, 'Look at Egypt,' and you don't need to say anything else."
From Benghazi to Abu Dhabi, Islamists are drawing lessons from Mr. Morsi's ouster that could shape political Islam for a generation. For some, it demonstrated the futility of democracy in a world dominated by Western powers and their client states. But others, acknowledging that the takeover accompanied a broad popular backlash, also faulted the leaders of the Muslim Brotherhood for reaching too fast for so many levers of power.
The Brotherhood's fall is the greatest in an array of setbacks that have halted the once seemingly unstoppable march of political Islam. As they have moved from opposition to establishment, Islamist parties in Turkey, Tunisia and now Egypt have all been caught up in crises over the secular practicalities of governing like power sharing, urban planning, public security or even keeping the lights on.
Brotherhood leaders -- the few who have not been arrested or dropped out of sight -- have little doubt about the source of their problems. They say that the Egyptian security forces and bureaucracy conspired to sabotage their rule, and that the generals seized on the chance to topple the Morsi government under the cover of popular anger at the dysfunction of the state.
Their account strikes a chord with fellow Islamists around the region who are all too familiar with the historic turning points when, they say, military crackdowns stole their imminent democratic victories: Egypt under Gamal Abdel Nasser in 1954; Algeria in 1991; and the Palestinian territories in 2006.
"The message will resonate throughout the Muslim world loud and clear: democracy is not for Muslims," Essam el-Haddad, Mr. Morsi's foreign policy adviser, warned on his official Web site shortly before the military detained him and cut off all his communication. The overthrow of an elected Islamist government in Egypt, the symbolic heart of the Arab world, Mr. Haddad wrote, would fuel more violent terrorism than the Western wars in Iraq and Afghanistan.
And he took aim at Western critics of the Islamists. "The silence of all of those voices with an impending military coup is hypocritical," Mr. Haddad wrote, "and that hypocrisy will not be lost on a large swath of Egyptians, Arabs and Muslims."
In Egyptian Sinai just hours later, thousands of Islamists rallied under the black flag of jihad and cheered widely at calls for "a war council" to roll back Mr. Morsi's ouster. "The age of peacefulness is over," the speaker declared in a video of the rally. "No more peacefulness after today."
"No more election after today," the crowd chanted in response.
After a night of deadly clashes at Cairo University that accompanied the takeover, some ultraconservative Islamists gathered there said their experiment in electoral politics -- a deviation from God's law to begin with -- had come to a bad end.
"Didn't we do what they asked," asked Mahmoud Taha, 40, a merchant. "We don't believe in democracy to begin with; it's not part of our ideology. But we accepted it. We followed them, and then this is what they do?"
In Syria, where the Egyptian Muslim Brotherhood once hoped to provide a model of moderation and democracy, some fighters battling President Bashar al-Assad now say it is the other way around. Egyptian Islamists "may have to pursue the armed option," said Firas Filefleh, a rebel fighter in an Islamist brigade in Idlib, in northern Syria. "That may be the only choice, as it was for us in Syria."
In the United Arab Emirates, where the authoritarian government just sentenced 69 members of a Brotherhood-linked Islamist group to prison in an effort to stop the spread of Arab spring revolts, Islamists said the crackdowns were driving a deeper wedge into their movement.
"The practices that we see today will split the Islamists in half," said Saeed Nasar Alteneji, a former head of the Emirates group, the Islah association. "There are those who always call for centrism and moderation and peaceful political participation," he said. "The other group condemns democracy and sees today that the West and others will never accept the ballot box if it brings Islamists to power."
"And they have lots of evidence of this," he said, now citing Egypt as well as Algeria.
Other Islamists, though, sought to distance themselves from what they considered the Egyptian Brotherhood's errors.
As the military takeover began to unfold, Ali Larayedh, the Islamist prime minister of Tunisia, emphasized in a television interview that "an Egypt scenario" was unlikely to befall his Ennahda movement because "our approach is characterized by consensus and partnership."
Emad al-din al-Rashid, a prominent Syrian Islamist and scholar now based in Istanbul, said that he "expected this to happen" because of the Muslim Brotherhood's style of governance. "The beginning was a mistake, a sin, and the Brotherhood were running Egypt like they would run a private organization, not a country," he said. "They shouldn't have rushed to rule like they did. If they had waited for the second or third elections, the people would have been asking and yearning for them."
Hisham Krekshi, a senior member of the Libyan Muslim Brotherhood in Tripoli, Libya, said the Egyptian Brotherhood "were not transparent enough. They were not sharing enough with other parties. We have to be sure that we are open, to say, 'We are all Libyans and we have to accept every rainbow color, to work together.' "
Even among Egyptian Islamists there have been signs of dissent from the Brotherhood leadership. The largest ultraconservative party, Al Nour, had urged the Brotherhood to form a broader coalition and then to call early presidential elections, and it finally supported the takeover.
Abdel Moneim Aboul Fotouh, a relatively liberal former Brotherhood leader and presidential candidate popular among many younger members, also urged Mr. Morsi to step down to defuse the polarization of the country.
But, said Ibrahim Houdaiby, a former Brotherhood member, "the feeling of exclusion might actually lead to the empowerment of a more radical sentiment in the group that says, 'Look, we abided by the rules, we were elected democratically, and of course we were rejected, and of course by a military coup, not by popular protest.' "
Reporting was contributed by Mayy El Sheikh and Kareem Fahim from Cairo; Hala Droubi from Dubai, United Arab Emirates; and Robert F. Worth from Washington.
Correction: July 5, 2013, Friday
This article has been revised to reflect the following correction: An earlier version of this article referred erroneously to Turkey in a passage about Islamist-led countries that have faced crises. Turkey's Islamist leader, Prime Minister Recep Tayyip Erdogan, has been in office since 2003; his party did not take power after the Arab Spring revolts.
This article originally appeared in The New York Times.