In no way shape or form do I think the US will do (or would do) that, and i have not indicated such. I agree with you in everything you said. It is whether the US can, and that is it. The original statement was that they cannot, and there is plenty of evidence and proof from the past that they can.
Why would they (US) in Nigeria? It wouldn't make sense. US wants oil from places outside the Middle East, plain and simple.