CAIRO — They are a desert king and a military officer-turned-president. Drive through their capitals and their images glow from billboards and painted walls, old men with their eyes fixed everywhere, even as whispers grow about who will rise to replace them.
King Abdullah of Saudi Arabia and Egyptian President Hosni Mubarak are in their 80s, durable U.S. allies whose governments have crushed political dissent at home while playing leading roles across the Middle East. But these days, talk of succession reverberates as Washington, as well as Riyadh and Cairo, plans to navigate an era without two of the region's dominant personalities.
The men have given no indication that they will step down. Mubarak's term runs until 2011 and the king's reign lasts for as long as he sees fit. But Mubarak and Abdullah are frail.
In Egypt, there is incessant chatter that the president's younger son, Gamal, will follow his father, and in Saudi Arabia, several leadership scenarios are unfolding within the ruling House of Saud.
A senior State Department official said the U.S. believes that its relationship with the two countries is "deep enough and broad enough to withstand the strains of any kind of transition."
But the official, who spoke anonymously because of the sensitivity of the matter, added that the eventual absence of Mubarak, who has been in power since 1981, and Abdullah, who took the throne in 2005 but has run Saudi Arabia since 1996, when the since-deceased King Fahd suffered a stroke, raises concerns about the future of a jittery Middle East.
The imprints the aging leaders have left are indelible. Mubarak has kept peace with Israel -- at a stiff cost to his domestic credibility -- while pushing for a Palestinian state. Abdullah has transformed his kingdom's oil wealth into diplomatic power as Riyadh, the Saudi capital, has become influential from Beirut to Kabul, Afghanistan.
The pair have brushed aside historical animosities between their nations to cooperate in confronting what they regard as major threats to the Sunni Muslim Arab world: the prospect of a nuclear-armed Shiite Iran and the violence sparked by Islamic militancy extending from North Africa to Indonesia.
Their overall strategies, which complement U.S. interests, are not expected to be significantly altered by their successors, especially since new leaders will almost certainly come from the ranks of the ruling regimes. What will vanish are decades of experience and the visages the world has grown accustomed to: Mubarak, 81, with his oversized sunglasses and Air Force salute, and Abdullah, 85, with his endless entourages and jet black goatee.
It is likely that Iran, Syria and their Islamist allies Hezbollah in Lebanon and Hamas in the Gaza Strip will move quickly to provoke whoever follows the two leaders. At the same time, domestic reformers and opposition groups, especially the radical Muslim Brotherhood in Egypt, are expected to push for broader political freedoms and to stem state security networks that have been criticized by international human rights organizations and Washington for torture, imprisonment and other violations.
"The U.S. should be worried about the possibility of either of these two leaders leaving the scene. Iran and Syria will move to exploit the loss of Mubarak and King Abdullah," said Amr Hamzawy, a Middle East expert with the Carnegie Endowment for International Peace.
But Nabil Fahmy, a former Egyptian ambassador to the U.S., said, "Egypt and Saudi Arabia have been strong supporters of an open relationship with the West -- and Washington in particular."
"I'm not as worried about the change of leadership as many in the West are," he said.
Topping the list of potential successors in Egypt are Mubarak's son Gamal, 45, and Omar Suleiman, who is in his early 70s, a longtime confidant of the president and head of the country's intelligence network. Gamal, a leading voice within the ruling National Democratic Party, lacks government and foreign policy experience but supports economic reform and appears more attuned to human rights than his father.
Suleiman has the institutional pedigree of Mubarak and previous Egyptian presidents and, as a chief mediator dealing with the Palestinians, has close ties with Washington. It is unclear, however, whether he wants to lead the country. He is also a reminder of a bygone Egypt, a time when Cairo, which is now slipping in stature, was the center of the Arab world.
Egypt's bonds with Washington, fueled by $1.2 billion in annual U.S. aid, have survived political transitions and tense relations.
"President Mubarak and George W. Bush didn't have great personal ties, but that never affected the strategic, military and security relations between the countries," said Diaa Rashwan, an analyst at Al Ahram Center for Political and Strategic Studies in Cairo.