A handout photograph released by the Egyptian Presidency shows Egyptian President Mohamed Morsi waving to his supporters as he attends a Syria solidarity conference organized by the Muslim Brotherhood, Cairo on June 15. (EGYPTIAN PRESIDENCY / HANDOUT/EPA)

He was young and bright, with an education from Egypt’s premier school of Islamic studies and lucrative job offers in the Persian Gulf.

But Bilal Farag chose a different path, friends say, one that led him to die on a distant Syrian battlefield while fighting Shiite Muslims he regarded as infidels.

“Everybody has their own goal in life,” said a close friend, Hosam Ali. “Bilal’s was to be a martyr.”

Waves of Egyptians are now preparing to follow, fired by the virulently sectarian rhetoric of Sunni preachers and encouraged by the newly permissive policies of Egypt’s Islamist government. In recent days, this city’s ancient mosques have crackled with calls for jihad, as hard-line Sunni Muslim leaders command the faithful to respond to recent escalations in Syria by the Shiite forces of Iran and Hezbollah.

The Sunni backlash has echoed far beyond Egypt, penetrating every corner of the region, where divisions between the rival Muslim sects are hardening fast. At the Grand Mosque in Mecca, Islam’s holiest site, the top cleric broke down in tears on pan-Arab television recently as he pleaded with his fellow Muslims to help the Syrian rebels “by all means.”

The role of Sunni foreign fighters in Syria

Foreign militants have long played a critical role in the Syrian uprising, but the prospect of a fresh flow of radicalized fighters bent on waging sectarian war threatens to complicate the Obama administration’s recently announced strategy to arm the rebellion’s moderate factions.

Although the United States and the Sunni jihadists share a common enemy — the government of Syrian President Bashar al-Assad, whose Alawite sect represents an offshoot of Shiite Islam — they have starkly different motivations. The United States is hoping to strengthen the rebels’ hand in advance of possible peace talks and to marginalize radical groups. Many foreign fighters, meanwhile, are seeking to defeat what they consider a deviant strain of Islam that they believe has declared war on the religion’s true adherents.

“This war is not only against Syrians. It is against the Sunni people all around the world,” said Adel Shokry, a 32-year-old lawyer who is contemplating joining the rebels after hearing a stinging denunciation of Assad and his allies at a Cairo mosque.

The vast majority of Egyptian Muslims are Sunni, but until recently, Egypt had sought to stay on the sidelines of the Syrian war. It was part of the shrinking middle ground in an increasingly polarized region. The nation’s Muslim Brotherhood-aligned president, Mohamed Morsi, had avoided sectarian rhetoric and had even carved out a possible mediating role by cultivating closer relations with Iran.

That changed June 15. Morsi, who has been under pressure from hard-line Islamists at home, used a stadium speech before thousands of supporters to rip into Assad, Hezbollah and Iran. As the crowd chanted, “Sunni blood isn’t cheap,” the president announced that he was cutting all ties with Assad’s government and that Egypt would provide support for the rebels.

Well of would-be fighters

Short on cash and facing growing internal discord, Egypt’s government is in no position to provide meaningful assistance. But as the Arab world’s most populous nation, one with an especially high proportion of unemployed youth, Egypt has a deep well of would-be fighters.

For three decades under President Hosni Mubarak, the government cracked down hard on militants seeking to leave Egypt to fight in foreign wars, such as Afghanistan or Iraq.

But that has changed under the Muslim Brotherhood and its allies, which came to power in last year’s elections, after the 2011 revolution that deposed Mubarak.

“Before, we would have to sneak fighters out of the country,” said Mohammed Hassan Hamed, a spokesman for Gamaa Islamiya, a radical Islamist group that waged an insurgency against the Egyptian government before officially renouncing violence in 2003. “But now it’s more comfortable for fighters to go to Syria. If they live through the war and come back, they know they are not going to be prosecuted.”

That, Hassan hastened to add, “is not a reason for Americans to be afraid.” Unlike in Afghanistan and Iraq, he said, the United States and the jihadi fighters are on the same side in this war.

But to many secular Egyptians, it is terrifying. “They’re going to get weapons and training, and one day they could come back to fight us,” said Khaled Salah, editor in chief of the secular-minded Youm7 newspaper.

Tellingly, Egyptian moderates such as Salah have been the loudest critics of Morsi’s decision to back the rebels. Liberal Egyptians who overthrew their own autocratic leader had been sympathetic with the uprising against Assad early on. But many now say they don’t know which side to support and think that Egypt should stay out of what they see as a sectarian conflict.

“The Middle East is shifting from a region that was dreaming of democracy to a battlefield between Shiite and Sunni,” Salah said. “It’s very dangerous.”

Syria, where the United Nations says 93,000 people have died since the conflict began two years ago, is not the only sectarian battlefield in the region. Iraq has seen an escalation of tit-for-tat killings in recent weeks, and an upsurge in violence in Lebanon has sparked fears that the war in Syria is spilling past its western border.

But Syria is undoubtedly the central fight in a dispute that dates to the 7th century, when followers of the prophet Muhammad fought over the line of succession after his death.

The region’s turn to sectarianism intensified late last month, when Hasan Nasrallah, leader of the Shiite Lebanese political party and militia Hezbollah, announced that the group was going all-in to support Assad and belittled Syria’s predominantly Sunni rebels as agents of Israel and the United States. About the same time, Iran acknowledged that its Revolutionary Guard Corps forces were operating inside Syria in support of the government. Iraqi Shiites, too, have joined the fight.

Both Iran and Hezbollah have been instrumental in recent battles that have turned momentum toward Assad. Far from conceding defeat, Sunni clerics across the region have rallied to the rebel cause. Yousuf al-Qaradawi, a charismatic Egyptian preacher who is influential within the Muslim Brotherhood, condemned Hezbollah as “the party of Satan” and sought to goad his fellow Sunnis into action.

“How could 100 million Shiites defeat 1.7 billion [Sunnis]?” he asked, referring to a global population balance that strongly favors Sunnis. "Only because [Sunni] Muslims are weak.”

‘Stunningly rapid’

While Assad has cast his opponents as foreign terrorists, no more than 10 percent of the rebel force is foreign, according to a study released this month by the Washington Institute for Near East Policy and Flashpoint Global Partners.

Still, that’s enough to make Syria the third-largest mobilization of Sunni fighters to a foreign cause in recent decades, “falling short only of Afghanistan in the 1980s and Iraq during the last decade,” the study’s authors write. “The difference this time is that the mobilization has been stunningly rapid — what took six years to build in Iraq at the height of the U.S. occupation may have accumulated inside Syria in less than half that time.”

And unlike in Iraq, where the vast majority of the foreign fighters were from Syria or Saudi Arabia, this time the three North African nations that experienced Arab Spring revolutions — Libya, Tunisia and Egypt — have all been amply represented.

Hesham El Ashry, a jovial former tailor who speaks English with a Brooklyn accent after spending 15 years in the United States, said he has been helping Egyptians travel to Syria for the past year. Most, he said, are members of the middle class or above who can afford a plane ticket and a gun — the two main requirements for any would-be fighter. He instructs them to fly to one of Syria’s neighbors and facilitates introductions with rebel groups that take the recruits from there.

“More will be going to Syria, because there’s no way for Bashar to win,” said Ashry, a community leader among hard-line Islamists known as Salafists. “And Syria will be established as a strong Sunni Muslim country.”

Word of an imminent influx of foreigners has reached the many refugee camps ringing Syria. There, young Syrian men say they’re headed back into the fight, now that they know reinforcements are on the way.

“The West has left us to be massacred by Iranians, Hezbollah and Iraqis,” said Mohammed Al Rifai, 22, as he waited in a Jordanian camp to board a bus destined for the Syrian border. “But now we are relying on our Muslim and Arab brothers coming from Egypt, Malaysia, Saudi Arabia, Somalia and elsewhere. They will be the ones who will save us.”

Sharaf al-Hourani in Cairo and William Booth and Taylor Luck in the Zaatari refugee camp outside Mafraq, Jordan, contributed to this report.