from trade to intellectual property theft to human rights? how does he see his leverage? >> reporter: two areas. the point christine made which is that we're china's biggest customer. that gives the u.s. some leverage. the second point may not be as clear at face value which is the fact that while a currency manipulation in the short term seems to really help china, what u.s. officials say in private is, look, it's also driving inflation through the roof in china right now. you see wages, the cost of goods are going sky high right now. and the u.s. believes china can't sustain that long term. so they're going to have to reform the currency, whether they want to do it or not, just for their own economic survival. secondly, we have to be skeptical when the u.s. continually says, we're going to be really tough in private. but in public, we have to be nice because that's the way you do this. we're not behind closed doors with them. we don't really know how tough they're being. but, in fact, there is a point as to why the u.s. has to be careful about how hard they push. and that's the fact that we have