RIYADH: Out of sight on a remote, scalding-hot air base in Saudi Arabia, some 5,000 American troops fly patrols over southern Iraq and defend this oil-rich desert kingdom.

Other unseen American forces man the Patriot antimissile batteries that ring the sandy capital, Riyadh, and other major cities. And American trainers, who call themselves “desert military diplomats,” continue to build the close US-Saudi alliance that began more than half a century ago.

“Members of the Saudi Arabian military are our trusted friends and vice versa,” the US military says in an official statement.

Although America provides Saudi Arabia security in exchange for secure access to Saudi oil, the extreme low profile is deliberate. It underscores a host of long-growing issues that have been magnified since Sept 11, overshadowing US ties with its most important Arab ally.

Officially, the two friends are all smiles and as close as ever. But unofficially, the act of balancing interests is getting trickier for both Washington and Riyadh.

Saudi officials rule out using any “oil weapon” to influence Washington. But at stake is Saudi support as Washington seeks to expand its declared “war on terrorism” to Iraq.

Tepid support for US missions against Afghanistan, deep and public unhappiness with unwavering US support for Israel, and public opposition to any military action in Iraq, have caused some ranking US officials to reexamine the scale of US forces in Saudi Arabia.

“Saudi Arabia feels they are in the cross hairs,” says a US official here.

Americans and Saudis alike have been scrambling to pick up the pieces since it became clear that 15 of the 19 hijackers were Saudi. Though Washington has yet to give an official breakdown by nationality of prisoners at Guantanamo Bay, Cuba, one US official here confirmed that more than one-third of the first 300 detainees were Saudis.

Saudi-born Osama bin Laden has called repeatedly for US “infidel” forces to be ejected from the land of Islam’s holiest shrines. US and Saudi officials say that the question of US forces moving has not come up at high-level talks. The focus of George W. Bush’s Texas summit with Crown Prince Abdullah was in fact Mideast violence, not unresolved questions about Saudi roots of the Sept 11 hijackers.

On Afghanistan, the official line on both sides is that the US never asked Saudi Arabia for permission to mount combat operations from Saudi bases, and that the Saudi’s have helped in every other way. Saudi sources say the US did request combat help, and was refused.

Even before Sept 11, the Pentagon was reportedly working on non-Saudi contingency plans.

Riyadh also opposes Washington’s policy of “regime change” for Baghdad. “Their view is that if the Americans get it wrong, you’ll end up with an irate Saddam who is a threat, or a pro-Tehran theocracy that is also a threat,” says Henderson. “And why deal with Saddam at all, if the US security guarantee is that the cavalry will come over the horizon anyway when the kingdom is in crisis?”

“Two more different societies never existed,” says a Western diplomat. He calls the Americans and closed-society Saudis “intimate strangers that can quite easily talk past each other — and easily rub each other the wrong way.”

In January, White House Chief of Staff Andrew Card told CNN that the Saudis have been “wonderful allies in this war against terrorism” — a view shared by many diplomats here — but that Riyadh had been “asking a long time” to reduce troop levels. “We are looking to reduce the footprint within Saudi Arabia,” he said, “consistent with America’s interests and consistent with the interests of Saudi Arabia.”

That view coincided with concern of the chairman of the Senate Armed Services Committee, Carl Levin, who said in January: “There’s a real problem when we’re told that a country that’s presumably an ally of ours doesn’t want us to be seen by its people.”

American forces moved to the remote Prince Sultan air base, after vulnerable city locations such as the US Air Force barracks at Al-Khobar were targeted by bombers in 1995 and 1996.—Dawn/The Christian Science Monitor News Service.