CAIRO • The Shi'ite leaders of Iran and the Sunni rulers of Saudi Arabia traded insults over the deaths of hundreds of Iranian pilgrims near Mecca. Bahrain's government, long criticised for repressing its Shi'ite majority, expelled Iran's ambassador after accusing Teheran of shipping arms to Bahrain and trying to foment "sectarian strife". And a group of hard-line Sunni clerics in Saudi Arabia, fired up by Russia's intervention in Syria, issued a scathing sectarian call for holy war.
Events over the past few weeks have raised fears of an accelerating confrontation between the Arab world's Shi'ite and Sunni Muslims, with Saudi Arabia and Iran escalating their power struggle, extremists attacking Shi'ite mosques in the Persian Gulf and armed conflict aggravating religious differences in Iraq, Syria and now Yemen.
But even as the violence flares and crosses borders, national and religious leaders seem as eager as ever to stoke the fires, mobilising followers using implicit or naked sectarian appeals that are transforming political conflicts into religious struggles and making the bloodshed in the region harder to contain, scholars and analysts say.
"This is unprecedented, and we don't have a road map," said Mr Rami Khouri, a senior fellow at the Issam Fares Institute of the American University of Beirut. "Radical individuals are deliberately fomenting this violence. And irresponsible governments allow it to happen."
The perils of sectarian polarisation have been evident for more than a decade, since the US-led invasion and occupation of Iraq. In the past few years, tensions have been inflamed by the war in Syria.
AN OMINOUS SITUATION
We are in this terrible moment of transition where sect is very high in people's minds. Radical individuals are deliberately fomenting this violence. And irresponsible governments allow it to happen.
MR RAMI KHOURI, a senior fellow at the Issam Fares Institute of the American University of Beirut
The Pentagon yesterday said a US-led air strike in Syria had killed Sanafi al-Nasr, a Saudi citizen and the leader of an Al-Qaeda offshoot called the Khorasan Group.
The latest violent turn in the region has been "ratcheted up by the Iranian-Saudi conflict", Mr Khouri said. Iran's latest broadsides over the pilgrims' deaths near the Saudi city of Mecca during the haj came as the Gulf states have taken an increasingly hard line against what they call Iran's meddling in the region - going so far as to mount a large-scale military offensive in Yemen aimed at defeating a rebel group they say is allied with the Iranians.
As the Sunni monarchies have rallied their citizens for war, the rulers seem ill-prepared for the potential fallout: Several times recently, Sunni extremists have carried out deadly attacks on Shi'ite mosques.
Also, Russia's decision to intervene in Syria alongside the government of President Bashar Assad, Iran and Hizbollah, the Lebanese Shi'ite militia, brought calls for retaliation not only from hard-line Saudi clerics known as Salafis, but also mainstream Islamist groups such as the Muslim Brotherhood in Egypt, which called Mr Assad a "treacherous Alawite criminal".
The Salafis, denigrating their adversaries, including Shi'ite Muslims and Alawites, who practise an offshoot of Shi'ite Islam, also took aim at the "Orthodox crusader Russia", which they said was picking up where the Soviet force driven from Afghanistan by Muslims more than a generation ago had left off.
In an online statement signed by 55 clerics, they warned that if the "holy warriors" were defeated in Syria, Sunni nations would also fall "one after the other".
Ms Madawi al-Rasheed, a visiting professor at the Middle East Centre of the London School of Economics, said the statement's strong sectarian tone represented the sort of pronouncements that have made the hostilities harder to arrest. "The language of sectarianism involves elimination and purification, and these are very dangerous words."
Mr Hassan Hassan, an associate fellow at Chatham House in Britain, said Russian involvement in Syria had the potential to be a "mobilising factor" for Sunnis, and not just extremists. There are ordinary people angered by the war and convinced that the great powers, including the US, are colluding to prop up Mr Assad's government.
The latest irritant is the war in Yemen, where a coalition of Sunni states, backed by the United States, is fighting a Shi'ite-led rebel group, the Houthis. The Saudi-led coalition is trying to restore the Yemeni government driven into exile by the Houthis. But it has also framed the intervention in part as an effort to beat back the influence of Iran.
Many outside observers, including former and current US officials, believe the Gulf states have wildly overstated the degree of Iranian influence over the Houthis. And the rebels, also exaggerating, have sent fighters, including teens, to battle, with the admonition that all their opponents are Sunni extremists.
Yemen has been left to face the war's ominous effects, including a sharpening of sectarianism. As states become weaker, the absence of a dominant political authority creates the conditions in which extremism and appeals to religious identity flourish, analysts say.
NEW YORK TIMES