Don't panic, I'm probably wrong here. According to Daniel Drezner,

As I've said recently, Al-Qaeda's current strategy of killing large numbers of Muslims makes little strategic sense. Stephen Den Beste recently offered up his explanation: "bin Laden's strategy was to get God, or Allah, involved in the war against the infidel."

That's two smart people who agree, and we all hope they're right. Drezner links to Den Beste so I don't need to. All the same, lets at least briefly consider a worst case scenario - Al Qaeda has strategic reasons for what they're doing.

Now clearly Al Qaeda is making strategic enemies of governments like Saudi Arabia who were in the past at worst lukewarm enemies. This would certainly make sense if those governments were much closer to being overthrown than we think. Saudi Arabia is a closed society, so it's hard to know. Just in the name of being prepared for the worst, it's worth thinking about.

How many hardcore supporters does Al Qaeda have in Saudi Arabia so enthusiastic they won't look at these bombings and figure it might be a relative? Not enough I suspect. If they have a strategy at all it involves fear as well as loyalty. If the government cannot protect their allies, then even people who hate Al Qaeda may lose faith in that government.

Of course they may be idiots. Maybe even Bin Laden is desperately wishing he could stop his franchises from doing this. But it's dangerous to assume so with no hard questions.