Saudi Arabia is deeply concerned about the coalition's push into Iraq. The presence of US bases in the country not only makes it a potential target for the Iraqis but also infuriates many in this overwhelmingly Muslim nation.
On Wednesday night a windstorm howled through the streets of Riyadh. The high-rise luxury towers of Mamlakah and al-Faisaliah, built by princes of the ruling house of Saud, costing billions of riyals, were lost in the swirling sand.
Riyadh is a sprawling, modern city
It was the same storm that blew into Kuwait, into the massed forces of American and British might poised for attack as time ran down on President Bush's ultimatum to Saddam Hussein.
The next morning I awoke early. The wind had dropped but the sand particles clung in the air and Saudi Arabia's twin towers were lost in the haze.
The war had begun. My hotel is close to the downtown area. It's guarded now and cars are being stopped and checked.
Across the street is the ministry of interior building. It looks like nothing more than a giant spaceship, hexagonal, huge and brooding, sitting on the desert floor as if it had just landed.
Riyadh is a sprawling city of congested motorways, gleaming government ministries, glass and marble office buildings and walled residential compounds, and towering over it all, Mamlakah and al-Faisaliah.
My taxi driver is a cheerful, enormously resourceful Bangladeshi called - well, I can't give you his name. He is afraid that the Saudi authorities will punish him. So let's just call him Bob.
Osama Bin Laden has support from extremists in the Kingdom
I had a problem with my mobile phone the day the war started and, so while I interviewed two Muslim extremists in my hotel room, Bob went looking for a replacement phone.
One of the extremists, with the cold eyes of a fanatic set deep in a lined face, told me that the war was the work of Satan. He said it was the beginning of a great jihad that will bring America, Satan, to its knees.
He told me that the mujaheddin, the supporters and followers of Osama bin Laden, are armed and ready.
This was no idle boast. I'd already been told that assault rifles, rocket launchers, grenades, and high explosives are brought into the kingdom from North Yemen by tribes who share a kinship and a long history of smuggling across a shifting border of sand.
The weapons are sold on the black market. A Kalashnikov in normal times sells for 1000 Saudi riyals, but these are not normal times. It's a seller's market. The price has jumped to 2500 riyals, about £400.
On Tuesday, at about one in the afternoon there was a loud bang. I've heard bomb blasts in Jerusalem and London. I thought, "that sounds like a bomb". But I didn't hear what I'd always heard before - the sound of sirens. So I dismissed it.
There are hundreds, if not thousands, of young Saudis who are armed and angry
In the evening the Ministry of the Interior released a brief statement. In a residential compound just a few miles east of my hotel, a bomb maker had blown himself up. In the wreckage of his flat the security police found 12 AK-47s, three hand grenades, two rifles, a pistol, a lot of ammunition and high explosives.
There are hundreds, if not thousands, of young Saudis who are armed and angry. They will act with or without the approval of the religious scholars. If this war is not mercifully quick, if al-Jazeera carries the raw images of Iraqi women and children killed by American and British bombs, the mujaheddin will strike.
It is a nightmare scenario for the House of Saud. Already the militants are quietly enraged. They believe that behind the scenes, the royal family is helping the American war effort.
The militants say the House of Saud has strayed too far from their rigid, unforgiving brand of Islam. And there will be a reckoning.
But first comes the reckoning with the infidels. The cold-eyed extremist tells me that if the war lasts for more than a few days, religious scholars will issue a fatwa urging a jihad on British and American expats in Saudi Arabia.
He tells me that the fatwa will allow attacks in Britain. It is a chilling moment and time to conclude the interview. The militants leave my hotel room.
The phone rings. It's Bob. He's in the lobby. I go down and meet him. We return to my room. He's got me an almost new mobile phone at a knockdown price. I'm an utter techno-luddite.
Bob, on the other hand, knows all about things like computers and mobile phones. And this phone he's got me works on voice command. Amazing!
Bob shows me how to enter a name, repeat it and presto, the person is there on the line. I'm so delighted I try it out on my friend.
"Virginia," I say peremptorily, and there she is.
Bob's face is wreathed in smiles, I'm like a kid at Christmas. I pass the phone to Bob so he can speak to Virginia.
"Don't worry", he says. "I'll look after him."
It's a strange and dangerous time in this strange, space-age city. I look out of my window, and I still can't see Mamlakah and al-Faisaliah. Then I look at Bob, and I start to feel normal again.