Following the Saudi Arabian authorities' announcement that they foiled an Islamic militant attack on Mecca, John Simpson reports on the mood in the country.
The public are shocked by the fact that this terrorist attack would have taken place in Mecca - in the holy city.
But I don't think we can be certain what the motives of these suspected militants were.
It is possible that they were based in Mecca and were going to carry out attacks in other places - perhaps even in Riyadh or in Jeddah where there's a lot of foreigners.
But we shouldn't simply take it at face value that they were planning an attack in Mecca itself - it suits the government to give that impression.
Anti-terror activities can be seen everywhere in Saudi Arabia
The Saudi authorities get very nervous about these kinds of domestic terror attacks. In May, suicide bombers killed 35 people in attacks in Riyadh.
There is a great anxiety that the continuation of these sort of attacks could destabilise the whole country.
As a result they have arrested, they say, around 600 suspects.
They have "re-educated" very large numbers of clerics who were inclined to preach rather fiery sermons about the war in Iraq and the role of the Americans - lecturing and threatening them in equal proportions.
And they are attempting to loosen up the controls on society to allow people to have other outlets rather than extremism.
The government has decided to let liberals in the administration have their say in all sorts of things
At least for the time being, the government's answer has been greater openness. But it does not hide the tension below the surface.
The conservatives in the government denied that the 11 September attacks in the US and the May suicide bombings in Saudi had anything to do with Saudis.
They threw up their hands and said it was nothing to do with them. This turned out to be wrong.
As a result they lost ground in the complex politics of Saudi Arabia.
The liberals had an answer and that lay in opening up society. So far they have won the day. But this is likely to be a long contest.
The May attacks brought a change of approach
Meanwhile the authorities are taking their domestic war against terror very seriously.
You see all sorts of signs of anti-terrorist activity - even during Ramadan, which is a period when everything is slowed down quite remarkably.
There are guards at every large building, checking the cars that come in.
There are armoured vehicles outside residences. There are all sorts of precautions to ensure that foreigners in particular are not going to be easy targets.
To a certain extent this is due to pressure from the Americans.
The Saudis are very angry about the way the Americans see them and the way the US seems to be turning away from them.
Yet they have taken assistance from the US and the UK about security issues.
The counter to any sort of insurgency like this is intelligence.
And as a result of greater co-operation with the British and Americans the Saudis seem to be getting that intelligence now.