RIYADH // Hosni Mubarak's decision to resign the Egyptian presidency has deprived Saudi Arabia of its closest regional ally, strained relations with Washington and framed a host of new challenges for the kingdom's foreign policy, particularly in its efforts to blunt Iran's regional reach.
Mr Mubarak's dramatic reversal of fortune after almost 30 years in power removes Saudi Arabia's principal partner in anchoring the longtime US-led security framework in the Middle East.
A big Saudi concern will be that Egypt's probable future preoccupation with internal affairs could weaken its essential role in the Sunni Muslim regional pushback to Shiite Iran's perceived meddling in Arab affairs, some observers say.
Asaad al Shamlan, an assistant professor of political science at Riyadh's Institute of Diplomatic Studies, said: "For Saudi Arabia, Egypt is fundamental" to this effort, which has been "more aggressive" in recent year.
But if Cairo turns inward as it transitions from dictatorship to democracy, Mr al Shamlan said, that "probably will slow the pace of that strategy".
Arab states will be watching closely to see how Iran may try to benefit from the unsettled Arab landscape created by Egypt's revolution, especially in places such as Yemen and Lebanon, according to Theodore Karasik, the director of research at the Dubai-based Institute for Near East and Gulf Military Analysis.
"Iran will try to take advantage of the spreading catharsis," he said, "and this will challenge the Saudi foreign policy establishment even more."
Meanwhile, Riyadh's relations with Washington appear troubled by what Saudi officials regard as the United States' lack of support for Mr Mubarak during the US ally's weeks-long duel of wills with street protesters demanding his departure.
King Abdullah bin Abdul Aziz let it be known publicly that he was backing Mr Mubarak against what the Saudi government-run news agency called "infiltrators" aiming to destabilise Egypt.
Last week in Morocco, the Saudi foreign minister, Prince Saud Al Faisal, appeared to also fault Washington, as well as European countries, when he deplored the "blatant interference by some foreign countries" in Egypt's internal affairs.
Even after Mr Mubarak's exit, the Saudi government offered no recognition of the pro-democracy rebellion that deposed him, saying only that the kingdom "welcomes the peaceful transition of power in the Arab Republic of Egypt, and expresses hope in the efforts of the Egyptian armed forces to restore peace, stability and tranquillity." The statement was carried late on Saturday by the state news agency.
It may be too soon to know how much Egyptian foreign policy will be affected by the country's new direction. But it seems clear that adjustments will be made. "A more democratic Egypt will mean a more scrutinised foreign policy from inside," Mr al Shamlan said. As a result, "different calculations will come".
For example, he said, "there is no doubt that you will find an Egypt which is more proactive in supporting Palestinian rights."
The pressing question of whether Egypt would continue to honour its 1979 peace treaty with Israel was answered on Saturday when a spokesman for the military, which now rules Egypt, stressed its "commitment to all Egypt's international treaties".
However, it is a political reality that Egyptian public opinion is hostile towards Israel because of its settlement building, its brutal war on Gaza in 2008, and its failure to negotiate a peace deal with Palestinians.
Khalid al Dakhil, a political scientist and columnist for Al Hayat newspaper, said: "Everyone will be euphoric if Egypt not necessarily withdraws from the peace treaty with Israel, but just gets very cold and closes the channels of contact with the Israelis, because people in this region are convinced more than 100 per cent that the Israelis are not interested in peace."
The unpredictable future course of the region comes at a sensitive time, with the Saudi king recuperating from back surgery outside the kingdom and recurring speculation among Saudis about who will rule them when he and the crown prince, both in their 80s, are no longer around.
Even before Egypt's revolution, the kingdom faced a bleak landscape in its neighbourhood.
Relations with Iraq, led by a Shiite government with close ties to Iran, remain frosty. In Lebanon, a prime minister backed by the pro-Iranian Hizbollah displaced the pro-Saudi prime minister, Saad Hariri, further straining Saudi ties with Syria. In addition the Palestinian Authority, which Riyadh favours over Hamas, was rendered inert and humiliated by Israel's intransigence. On Saturday, its chief negotiator Saeb Erekat resigned after leaked documents offered evidence of the futility of Palestinian concessions in talks with Israel. The papers also confirmed the authority's cooperation with Mr Mubarak and Israel to pressure Hamas, which controls Gaza.
Some Saudis said they were confident that despite Egypt's domestic turbulence, it will reassert its heavyweight status in regional affairs, rallying the Arab Sunni bloc against Iran and leading it away from being a parrot of US foreign policy.
For the moment, however, when it comes to predicting what is an uncertain future, Mr Karasik said, "we're in territory where everyone is right and everyone is wrong."