prospect of hitting the united states, obviously, you know, taking action in self defense is an international right. but i think part of what we're doing here is obviously a signal to north korea. if you pull a trigger, we're going to respond. but it's also making sure that we reassure south korea and japan. at the end of this, however it ends, we want to make sure that the security fundamentals that have protected us and our allies for decades, they continue. for example, if south korea wasn't sure about our willingness to protect them, they might say, well, if north korea is going to hold its nuclear weapons, we need some. if japan goes the same way, china has to recalculate. i think we're trying to make sure there is not a spiral that raises the floor so you have a kind of permanent escalation and a permanent and elevated state of risk. >> how important is china in all this? should china be doing more to get north korea to put a cork on it? >> i think, piers, you're right.