DUBAI (Reuters) - Popular protests in Bahrain may finally dislodge the world's longest-serving prime minister, as demanded by a mainly Shi'ite movement pressing for a fairer deal in the Gulf Arab island ruled by a Sunni Muslim dynasty.
Inspired by the fall of seemingly impregnable leaders in Egypt and Tunisia, Bahraini demonstrators want to see the back of their prime minister, Sheikh Khalifa bin Salman al-Khalifa, entrenched in office since independence from Britain in 1971.
He symbolizes the kind of stability which has sustained Arab states underpinned by unsavory security services and which has long suited the West, focused on securing global oil supplies.
Bahrain's oil industry, the first in the Gulf region, dates to 1932. Now only a small producer, the island is a strategic U.S. military asset, hosting an American naval base since 1958.
The Fifth Fleet's base near Manama helps Washington project military power across the Middle East and Central Asia. It has played a critical role in U.S.-led wars in Iraq and Afghanistan.
Sheikh Khalifa, 75, who many Bahrainis believe has acquired vast wealth and tracts of land during his tenure, looks increasingly unlikely to survive the crisis rocking his country.
"He has stayed long enough," said Abdel-Khaleq Abdallah, a political science professor in the United Arab Emirates.
"The king will probably find this as good a moment as any to say, thanks uncle, you have done your duty, time for you to make a move. We might see a new prime minister in the making soon."
U.S. President Barack Obama, rapidly reassessing policy as popular fury against Arab despots sweeps a long-dormant region, has condemned violence in Bahrain and told its rulers that stability depends on respect for the rights of its people.
"Obama has recognised this is not the time for autocrats and wants to side with democrats in the Arab world," Abdallah said. Nowhere had protesters chanted "Death to America," he noted.
Nor has Bahrain's roughly 70 percent Shi'ite majority, sore about what it calls decades of discrimination under Sunni rule, sought regime change, only a genuinely constitutional monarchy.
But protesters do want the resignations of the prime minister, along with the ministers of defense, interior and royal court, who they blame for crackdowns on Shi'ite dissent.
The government, which rules 1.3 million people, half of them foreigners, denies that Shi'ites get unequal access to health care, housing and state jobs, especially in the security forces.
Sheikh Khalifa has stayed curiously silent in the week-long conflict pitting Bahrain's police and army against protesters, in which six people have been killed and hundreds wounded.
King Hamad bin Isa al-Khalifa, 61, who took over in 1999, has entrusted his son, Crown Prince Sheikh Salman bin Hamad al-Khalifa, with opening a dialogue with the opposition to get people off the streets and heal Bahrain's still-raw wounds.
"All political parties in the country deserve a voice at the table," the crown prince told CNN on Saturday, extending condolences to the families of the dead and to the wounded.
He said protesters would "absolutely" be allowed to stay in Manama's Pearl Square, the fulcrum of demonstrations in Bahrain, similar to the Egyptian protest base in Cairo's Tahrir Square.
Shi'ite opposition parties and youthful protest organizers still seem leery of entering talks until the cabinet goes.
That alone may not be enough to calm the ferment. Among other demands, protesters have called for constitutional changes so that the government is elected, not appointed by the king.
"After the government has quit we can start a dialogue," said Zainab Ahmed, a member of the February 14 youth movement.
The crown prince, seen as a moderniser, chairs Bahrain's Economic Development Board, which he has turned almost into a parallel administration to foil resistance to economic reform.
In 2008, in a rare public spat, the king told his uncle's government not to delay reforms sponsored by the crown prince.
The king and his son may have sought to trim the prime minister's powers, but Sheikh Khalifa could have powerful allies in Saudi Arabia, just across a man-made causeway from Bahrain.
"They've known him for a long time and they've no interest in seeing a precedent for a senior royal retiring," Jane Kinninmont, at the Economist Intelligence Unit, said of a Saudi gerontocracy grappling with its own succession problems.
Nor would Riyadh relish the emergence of a Gulf monarchy subject to a democratic constitution, especially in a neighbor with a Shi'ite majority that could vote its way to power.
Saudi Arabia, which lost a key ally against Shi'ite Iran in Egypt's former President Hosni Mubarak, is concerned about any unrest spilling over to its own restive Shi'ite minority.
Bahrain's Sunnis, some of whom have staged loyalist demonstrations in the past week, might also fear a loss of power and privilege if Shi'ites gained full political inclusion.
King Hamad introduced a constitution in 1999 that provided for an elected assembly with some powers. But he still names the prime minister directly -- and 14 of Sheikh Khalifa's 24 cabinet ministers share the ruling family's name.
Bahrain, unlike Egypt, has held elections generally viewed as free and fair. Wefaq, the main Shi'ite bloc, held 17 of 40 assembly seats until all its MPs resigned on Thursday.
Yet restoring stability in Bahrain may be impossible unless the prime minister goes and perhaps others with him.
"It's a demand of the opposition to change the government," said Abdallah, the political scientist. "Once the head changes you will have a lot of other heads rolling down with him."
(Additional reporting by Frederik Richter in Manama; editing by Tim Pearce)