Saudi Arabia moved speedily last Monday to name 77-year-old Prince Salman bin Abdul-Aziz al-Saud, the country’s defence minister and half-brother of King Abdullah, as crown prince, to succeed the 89-year-old monarch.

Salman’s appointment follows the death of the previous heir apparent, Prince Nayef bin Albdul-Aziz al-Saud, who was the country’s de facto ruler, as King Abdullah himself is in extremely poor health. Nayef, an arch conservative and brutal oppressor of the Kingdom’s Shi’ite population, was responsible for the country’s notorious internal security, and won praise from Washington for his crackdown on Al Qaeda between 2003 and 2006.

Salman, the owner of a media empire, remains the country’s defence minister. At the end of last year, he signed the largest-ever arms deal with the US, worth US$90 billion, up from the previously announced US$60 billion. The deal includes aircraft and ships to modernise its Eastern Fleet, headquartered at Jubail, in the oil-rich Shi’a-populated Eastern Province.

Salman’s younger brother, the 72-year-old Prince Ahmad, will take over Nayef’s role as interior minister, a move widely seen as confirming him next in line after Salman.

But while this change in leadership portends no change in the House of Saud’s policies either at home or abroad, there are broader concerns. Salman is the third crown prince in the last year. He too is in poor health, having suffered at least one stroke that left him bedridden for weeks and has undergone surgery on his back.

Hitherto, the succession has passed between the sons of the country’s founder, Abdul-Aziz, but their immediate successors and their families, believed to number 20,000, are themselves well into their 70s or middle-aged. Isolated from the broad mass of the population—there was an attempted assassination in 2009 of the counter-terrorism chief—the princes are embroiled in factional rivalries and divisions.

Indeed, not a few commentators have pointed out that the turnover of crown princes is even more rapid than that of the aging leadership of the former Soviet Union from 1982 to 1985.

Abdullah created the Allegiance Council in 2006, made up of 34 princes, each representing a son of the founding King Abdulaziz, to decide the succession question. But it is nothing but a rubber stamp for his decisions.

This has raised widespread fears about the stability of the Kingdom, one of Washington’s key allies in the oil- and gas-rich region, on whom it depends in its ongoing efforts to establish its unchallenged global hegemony. Riyadh, along with the other Gulf monarchies, provides the crucial Sunni axis against Shi’ite Iran and its allies: Syria, Hezbollah in Lebanon, and Iraq’s powerful Shi’ite parties, which the US views as a regional threat.

The House of Saud, the largest family business in the world, presides over the world’s leading oil producer and exporter, with the largest known reserves in the world.

This medieval and venal monarchy maintains its grip on power by a system of brutal repression, including public executions, torture and detention without trial, and outlaws all public protests, strikes and expressions of dissent. This is combined with its championing of an extreme version of Sunni Islam, Wahhabism. Just last week, a man was executed for allegedly practising witchcraft and committing adultery.

Few apart from the ruling clique have derived much benefit from its oil wealth. According to official statistics, 11.6 percent of Saudi men are unemployed, but the real figure is several times higher. Young people under 30, who make up two thirds of the 26 million-strong population, are badly affected; 40 percent of 20- to 24-year-olds are unemployed. Even well-educated graduates cannot find work, marry or set up a home. Large numbers of women are excluded from the labour market, while most women live severely socially circumscribed lives.

While rising oil prices created 2.2 million new jobs in the private sector, only 9 percent went to Saudi citizens. Nearly 6 million workers, or 80 percent of the workforce, are non-nationals, mainly migrant labourers from South or Southeast Asia, who work for a pittance, without rights or protection.

The 10 to 15 percent of the population who are Shi’ite are persecuted. This has created deep social tensions, especially as the Shi’a live mainly in the Eastern Province, where 90 percent of Saudi’s 260 billion barrels of proven oil reserves are located.

In other words, no less than in any of the other countries in the Middle East, the House of Saud sits upon a social tinderbox.

Riyadh’s backers in Washington are well aware of the situation, as the State Department’s Annual Report to Congress on International Religious Freedom in 2010 makes clear. Confirming the situation in the Eastern Province, it reports arbitrary detentions, mosque closures, and the arrest of Shi’ite worshippers, while diplomatic cables released by WikiLeaks revealed that US diplomats in the country are acutely concerned by the grievances that they view as entirely legitimate. But such concerns are never raised with Saudi officials.

Following the mass social movements in Tunisia and Egypt, and just days after protests broke out in neighbouring Bahrain in March last year, protests began in the Eastern Province.

These were met with brutal suppression, with Nayef vowing to crush the protests with an “Iron Fist” and launching a vicious campaign against protests and the Shi’ite population.

While there is little coverage of the internal situation in Saudi Arabia by the regional news channels, all of which are controlled by the Kingdom—indeed, one of the major media owners is the new crown prince Salman himself—or its Gulf allies who depend on Riyadh’s support, protests started again last October and are believed to have been ongoing for months in the region around Qatteef. Security forces cracked down on the dissent, killing at least seven Shi’ite Muslims and wounding dozens more, leading to further mass protests.

Oppositionists made up of Saudi Shi’ites, both reformists and Islamists, have long called for an end to sectarian discrimination and more general political reforms. These demands have since expanded to include a withdrawal of Saudi forces from Bahrain and the release or retrial of nine Shi’ite political prisoners, incarcerated since 1996 on allegations of involvement in the bombing of Khobar Towers that killed 19 US servicemen. None of the evidence against them has ever been made public.

The divide-and-rule policies of sectarianism and the brutal repression of the Shi’ites are the essential props of a monarchy that has no political legitimacy or broad popular support. For the same reason, they also play a significant role in Saudi foreign policy.

For decades, Riyadh has used its enormous oil wealth to cultivate Sunni Islamic clerics and Salafist groups and finance campaigns of religious education and television programmes broadcast throughout the Middle East and Central Asia. It has whipped up hostility to the Shi’a minorities to divide any domestic dissent, prevent the growth of pro-Iranian Shi’ite political parties and counter Iranian influence, while routinely blaming Iranian “interference” in Bahrain and the Yemen for the unrest there, without producing any evidence.

Saudi Arabia has functioned as the linchpin of social reaction during the mass protests that have shaken the Middle East. Its overarching aim is crush all protests before they spread to Saudi Arabia and other Gulf States, all of which face dissent—including from their own restive Shi’ite populations. It was for this reason that Riyadh sent its troops into neighbouring Bahrain to suppress the Shi’ite revolt there in March last year and prop up the ruling Sunni dynasty.

Its sectarianism also plays a crucial role in its bid for regional dominance against Iran, which includes fomenting religious strife in Syria and Lebanon, in which the House of Saud uses its guardianship of two of Islam’s three holy sites to bolster its claim to defend the Muslim faith. With the support of the other Gulf monarchies, it portrays its struggle against Iran as a religious conflict against “heretical” Shi’ites so as to preserve its eastern front and maintain its wealth.

But this comes at a cost. Defence takes nearly a third of the Saudi budget. This is set to rise in line with the Kingdom’s increasingly bellicose attitude towards Iran, its involvement in Yemen and Pakistan, and covert funding of Sunni forces in Iraq and Syria. In addition, Saudi Arabia is committed to paying most of the US$25 billion the Gulf Cooperation Council (GCC) has pledged to buy off social discontent in Bahrain, Egypt, Jordan, and Oman. Riyadh also provides large sums to the Palestinians and Afghanistan.