Resources, and therefore trade of those resources, are necessary for the country to function. Corporations don't exist in a vacuum separate from other considerations. They don't, for example, care about oil in and of itself. Yes, they make money on it, but only because petroleum and it's byproducts are a necessary feedstock at all levels of the global economy. Reducing complex issues of geo politics and economics to "corporate greed" is overly reductive. Demand for their products is what gives rise to them in the first place. I'm not saying corporations don't influence things, but they cannot be isolated and analyzed separate from the system in which they operate. Google wouldn't have much influence on foreign policy in the middle east. Oil companies have influence there precisely because there are factors outside of their corporate greed that makes them relevant. Things just aren't as simple as "because money".