Had an interesting (and frightening) conversation with an Islamic friend . . .?

You are probably going to get nailed by disbelievers here, but in my professional opinion your friend is not only absolutely normal, he is absolutely correct. I believe a domino effect would occur. Israel would be gone and conflict between Muslim countries would result in one becoming the dominating power (Iran, Saudi Arabia, Syria, or Turkey). Regardless of which one, there would be no oil coming this way.