What in fact we see is a very great public response to such disasters as the Japanese earthquake and tsunami.

True, but first of all, the situation posited is one in which China is "swallowed up". If a disaster occurred, and there was no clear way for the generous public to actually help, do you think you would see the same response? I'm sure you would still have the same loud proclamations of tragedy and sympathy, but would there be action to match it? I suppose it's possible that they would try to support the remaining Chinese who presumably survived by not being in China, but it seems unlikely to me that the same concerted aid efforts would exist.

Secondly, it seems to me that Smith is talking more about genuine emotional distress and lasting life changes than simply any kind of reaction. Yes, people donate money for disaster relief, but do they lose sleep over it? (Yes, there are some people who drop everything and relocate to physically help, but they are the exception.) Is a $5 donation to the Red Cross more indicative of genuine distress and significant change, or the kind of public sympathy that allows the person to return to their lives as soon as they've sent the text?