The Bush family has a longstanding business relationship with the royal family of Saudi Arabia ('The House of Saud'). That's why they are called 'our friend in the region', because they sell the oil cheap to Bush's friends. So there would be no point in invading them.
However, Saudi Arabia is growing unstable. The wealth in the country is highly concentrated, with the royal family and their friends being super-rich and the other 98% of the country desperately poor. The population of Saudi Arabia is growing younger all the time (average age), and most people under 30 -hate- the government. Some people think it's only a matter of time before there's a revolution there.
If that happens, of course the Bush admin. (or probably -any- American president) will say the revolutionaries are 'terrorists'. You'll hear the same stuff you head about Saddam, that they have WMD, that they are planning to take over the whole region, or the whole world, that they are planning to invade the US, all that baloney.
Of course our govt. will want to bring US military force to bear to protect their friends (I mean their -real- friends, the oil companies). We had a lot of troops and equipment stationed there but Bush pulled them out after 9/11, so you have to wonder how well we could protect the Saudi royals, especially with all the trouble we're having with Iraqis.