Because as much as we'd like to pretend otherwise, there are significant ideological differences between the US and China. China just enacted a 3 month ban on all spy dramas on TV [1] and I'm about go home and watch Casino Royal with a bottle of scotch [2]. And as JFK says, our leadership in science and in industry, our hopes for peace and security, our obligations to ourselves as well as others, all require us to make this effort, to solve these mysteries, to solve them for the good of all men, and to become the world's leading space-faring nation. [3]. This may seem nationalistic to you, but I think JFK is right.

[1] http://www.nytimes.com/2011/05/06/world/asia/06briefs-China....

[2] Citation not needed.

[3] http://er.jsc.nasa.gov/seh/ricetalk.htm