Here is Eastern Province, where most of Saudi Arabia's huge oil riches lie deep under the desert sand, the ruling Sunni Muslim monarchy faces an increasingly resentful Shia Muslim minority.
Saudi officials, United States diplomats, and representatives of the Aramco Oil Company are concerned that deep-seated discontent among the 125,000 Shia Muslims of Eastern Province might endanger the security of the oil industry.
Aramco keeps no statistics on the religious compositions of its employees, but officials privately estimate that 40 to 60 percent of the work force are Shia Muslims. And the officials describe the Shia population here as "extremely angry."
Twice in the past three months the Shia population of the oasis around the township of Qatif, about an hour's drive north of Dhahran, have taken to the streets to express their grievances.
Carrying portraits of Ayatollah Ruhollah Khomeini, the Shia Muslim leader of revolutionary Iran, they demanded last November a fairer distribution of wealth within the Saudi kingdom and an end to alleged discrimination against Saudi Arabia's Shia minority by the Sunni majority.They took to the streets again for two days earlier this month.
It is not clear how much the Shia revolution in Iran has seeped across the waters of the Gulf. But, as an analyst here points out, the Saudi Shias "feel neglected by the House of Al Saud." He adds, however, that "it is unclear whether they are simply demanding what they conceive as justice from the royal family or the overthrow of the monarchy."
The Shias feel that Saudi Arabia's oil should remain in the ground because "the revenues are not coming back to those who work in the oil fields."
A Western diplomat comments: "There is no cause to be alarmed in the sense of an Iranian-type revolution in the near future." But, he adds, "the danger of sabotage of the oil fields cannot be excluded."
Some experts compare Saudi Arabia's Shia Muslims to the Palestinians or the European Jews, pointing out that "they are never given credit for the work they have done; nobody ever says "thank you' to them."
These sources fear that recent events in Eastern Province might have a snowball effect. Demonstrations at the end of November in Qatif resulted in armed clashes with the National Guard. Casualty figures are not available, but hundreds of Shia Muslims are believed to have been arrested.
The two days of demonstrations during the first week of February passed peacefully. But observers point out that this time the release of the detained Shias was added to the list of demands.
Although the Saudi authorities hope to reduce tension by dealing with the Shias' major grievances, some officials take a pessimistic view of the future. "No matter what the Saudis do, some of the Shias will say that it is not enough or that it is too late. It is a perception problem."
Moreover, in diplomatic and Saudi government circles there is concern that foreign powers are trying to exploit the Shias' grievances for their own purposes. "They are a happy hunting ground for the Palestine Liberation Organization, once the Palestinians turn on Saudi Arabia and the United States," a diplomat in Riyadh says.
It is asserted here that in the past year PLO officials have hinted at creating difficulties in the kingdom should Saudi Arabia not pressure the United States into "truly solving the Palestinian question."
However, it is more generally assumed that post-revolutionary Iran plays an important role in fueling the situation. Radio Tehran's daily Arab-language programs are widely listened to in Eastern Province.
In past weeks, the program has attacked not only the "United States, the bloodsuckers of peoples" but also the Saudi monarchy as a "corrupt, mercenary agent of the United States.
"The foreign policy of this [Saudi] regime is a satanic policy and is under the complete domination of the world- devouring America," the Iranians charged.
"In this country, there is an American dictatorship in force carried out by the members of the Saudi family under the name and cover of Islam, which does not allow any kind of feedom. There is no constitution, and the oppressed people of this land are even deprived of the basic necessities of life and basic rights while the rulers are forcefully using all their vast wealth of the land for their own gain."
Frequently Radio Tehran broadcasts statements by the "Islamic Revolutionary Organization of the Arab Peninsula," a hitherto unknown organization. Western diplomats believe that "it smells of a fake."
Immediately after the recent disturbances in Qatif, the Islamic Revolutionary Organization announced that "the Islamic revolution in the Arab peninsul a will continue to escalate until the tribal Al Saud regime is defeated and the Islamic republic is established upon the ruins of this oppressive regime."