Saudi Arabia IS a full member of the WTO, and has been since 2005. Look it up. Most OPEC states are- again, you can look this up. Use google. Don't just 'invent' whatever facts you find convenient. So is Kuwait. So is Venezuela. So is Qatar. So is Nigeria. ....

When did I say anything about the Sherman anti-trust act? If you are not going to respond to my points, why don't you just talk to yourself out loud in a corner? If Buck said something about the Sherman Anti-Trust act, go talk to him about it.

Regarding the WTO:

1) Most members of OPEC are in the WTO
2) Member states of the WTO agree to cede implementation, administration and operation of trade agreements under by the WTO TO the WTO
3) The WTO provides a mechanism (including punitive measures) for settling trade disputes of WTO covered trade agreements.
4) One primary rule under WTO membership is that a nation must apply the same trading standards to all nations who are also in the WTO (Does the word 'Embargo' come to mind here? Hmm?)
5) Another primary rule under WTO membership is that domestically produced goods must be handled the same as foreign produced goods, and VsVs. (Does the term 'Price Controls come to mind here? Hmm?')
5) A final primary rule (or doctrine) the WTO applies is 'Fair Competition' (Does the word 'Monopoly' ring a bell?)

If the OPEC member states want to keep their status in the the WTO- which given that well over 90% of both manufacturing and markets are in the WTO, and given that many of the opec states are very rich and don't want to be gouged, then indeed pressure can be brought to bear on OPEC via the WTO. If any on their petroleum exports are covered individually under WTO trade agreements (which, given thats about all most of them HAVE to trade!) then they are to some degree vulnerable to this pressure.

The WTO is selective in what it enforces, that is my main beef with the WTO. It tends to aggressively protect the interests of some members at the expense of others (and I think the US comes out with the short end of the stick too often!). I'm sure it is quite willing to turn a blind eye to the activities of OPEC, or consider the OPEC agreements to be outside the scope of the WTO because of it being currently convenient to do so. International Politics, which the republicans understand about as much as an infant understands adult psychology, is the art of making things less or more convenient for other nation states and bodies. I'm sure the WTO could be moved. It would be a significant effort, but it could at least pressure OPEC to give up some of its monopolistic tendencies.

Additionally, to point out again- OPEC is not anything like what it used to be 30 years ago. Its had a resurgence of late, but the amount of international oil production they control is shrinking.