Like the crude oil that lies in vast pools beneath the Persian Gulf,tensions between the regions Sunni and Shia Muslims tend to stay below ground. But when pressures build and a ready channel is cleared,they can bubble to the surface with alarming force. Thirty years ago the Islamic revolution in Shia-majority Iran inspired a wave of unrest among fellow Shias of the opposite shore. Things then calmed down. Nervous Arab rulers,all of them Sunnis,soothed their Shia subjects with a few rights and promises of more,while Iran largely gave up trying to export its revolutionary fervour.
But with Iran lately sounding more aggressive under President Mahmoud Ahmadinejad,small incidents are again triggering bigger eruptions. On February 20th,for instance,a group of female pilgrims visiting the most revered Shia site in Saudi Arabia,a cemetery in Islams second-holiest city,Medina,where hundreds of the Prophet Muhammads descendants are said to have been buried,screamed when they spotted what they guessed was a religious policeman filming them from on top of a security wall. Male relatives,outraged by this invasion of modesty,demanded the footage. Instead,the all-Sunni police force arrested five of them,sparking a riot by thousands of Shia pilgrims,more arrests and injuries. Repeated protests over several days then spread from Medina to Saudi Arabias Eastern Province. That province contains many of the kingdoms Shia minority,numbering about 10 per cent of Saudis,as well as most of its oil reserves.
As Shia clerics weighed in with calls for an end to what they called systematic persecution,Sunni extremists accused the rafida,an abusive term for Shias,meaning rejectionists,of acting as a fifth column for Iran. Today they besiege the religious police, howled one website commentator. Tomorrow they will encircle the Eastern Province along with the Shias of Bahrain and with Iranian backing. The Saudi king should strike them with an iron fist,declared the writer. Another suggested that the Shias be hurled into the Red Sea or,better still,dropped onto the Iranian shrine city of Qom.
Mention of Bahrain carries particular resonance. It was in this tiny neighbouring island kingdom,where two-thirds of the citizens are Shias and where the American Fifth Fleet is based,that sectarian troubles loomed alarmingly in the 1980s. More recently,in December,Bahrains authorities accused 35 Shias of plotting to overthrow the state. Since then,sporadic riots have rocked the poor Shia villages that ring Bahrains capital,Manama. In January three human-rights campaigners were arrested. This week 21 people,including two of the human-rights activists,appeared in court,accused of planning to ambush policemen and bomb public property,shopping malls,markets and hotels.
Yet when Iranian politicians recently sniffed that Bahrain used to be an Iranian province,Bahrains main Shia parties were quick to reaffirm their Arab identity,joining a chorus of Arab protest that led some commentators to remark pointedly that several Iranian provinces happen to house large Arab and Sunni populations. Fearing damage to the reputation it has tried to build as a defender of pan-Islamic causes,Iran hastily apologised to Bahrain.
The ugly nearby example of sectarian strife in Iraq,though it has subsided in the past two years,has left little appetite in the region for more trouble of that kind. Despite suspicions of their loyalty,Shia Arabs tend to look not to Iran but to their own spiritual leaders for guidance. Yet with Iran determined to chase the Arabs American ally from the Gulf,and with Shia Arabs often still suffering political exclusion and social stigma,unrest is likely to break out from time to time. Considering local,regional and international variables,a clash between the Saudi regime and its Shia citizens is a matter of time,reads an ominous analysis on a popular Saudi website.
© The Economist Newspaper Limited 2009