Janet Jalil

How likely is that, do you think, Frank?

Well, the Saudis have got a powerful air force and, of course, they've got a huge ally in the United States.

They are getting hit almost daily by Iranian ballistic missiles aimed at Prince Sultan Air Base south of Riyadh at a place called Al-Kharij.

And they're getting fed up with this and not being able to retaliate.

But they also know that...

If they were to join in this war, effectively on the side of Israel, that brings two risks.

One, their own population are not going to be happy at them appearing to side with Israel, a country that has been embroiled in the Gaza war since 2023.

And secondly, there is the risk of massive Iranian retaliation.

And the Saudis had a bit of a wake-up call in September 2019 when, having joined in the Yemen war to try and beat the Houthis,

They then got hit by a flurry of drones launched from Iraq by Iranian-backed proxies.

Iran always denied it, but I think everybody assumes it was Iranian-backed proxies that launched these drones at Saudi Arabia's petrochemical facilities.

And that knocked out half of Saudi's export capacity for several days.

Now, that was just a taste of what could possibly come.

So the Saudis know that they are vulnerable.

They've got good air defences.

They were able to shoot down the eight ballistic missiles that Iran fired at Riyadh a couple of days ago.

But not everything is able to be shot down.

Some things get through, and the damage to their critical national infrastructure could be catastrophic.

Frank Gardner in Doha.

Well, we've already seen how damaging attacks on energy infrastructure can be, with this week's soaring gas and oil prices and stock market falls after that Iranian attack on Qatar's main site for producing liquefied natural gas.