We want to get off of foreign oil, correct? Then why don't we drill here for it? I mean, within the U.S. (on land)?
I imagine for the same reasons a meth addict doesn't choose to make his own meth rather than buying from the dealers. He doesn't have the knowledge or means to sustain his addiction forever, and once it runs out or collapses he's back at the dealer's, anyway. Instead the healthier thing to do would be kick the addiction altogether, instead of making it from home.