It is a global market, and once the stuff is out of the ground, it will go to the place where the margin is highest—ships are rerouted on the high seas and sent to destinations—as is refined product.
The question of whether either national governments or OPEC in particular is able to influence the price of crude is both fascinating and very complicated. There's almost certainly no question that they are able to, in the short run, and I think some of the run-up that we've seen in crude prices is maybe a result of market manipulation. The evidence, if you go back to the 1970s, demonstrates that you can exert market power for a relatively short period of time. It's very difficult to exert market power over periods of a decade.
The only reason I would personally wonder if the future is going to be different from the past is that reserves today are so highly concentrated in a small number of companies, where access is either limited only to state oil companies or is very closely controlled by the government. You have a lot of oil in places like Saudi Arabia, Venezuela, and so on, and that does give you pause to wonder if maybe this episode will be a little bit different from the 1970s.