Or maybe, as many people have argued, Saudi Arabia realized that OPEP (and the non-OPEP players) are simply not disciplined enough to bring their production dow

Or maybe, as many people have argued, Saudi Arabia realized that OPEP (and the non-OPEP players) are simply not disciplined enough to bring their production down enough to move prices up. So they've decided to fight for market-share this time. And they can, since their production prices are on the low side.