After the display put on by 84 yesterday (amazing), I see lots of "US ain't winning".
My opinion... JH84 is one guy. I think the US might have the deeper field... based on country. Keep in mind that the MXGP field gets broken up. So while they might have a couple faster guys overall, are they all from the same country?
Saying that, the MXDN is a team race and there are several countries, including the US, that can win.