Missing another choice: Identify collision course threats and develop robotic technology to enable construction of 1) high delta-V high-resolution scouting missions, 2) long-term locally fueled, long-term robotic propulsion and steering bases to move those asteroids out of the way.
These would also seem to involve serious searches of both hemispheres, development of construction techniques for space and other planetary bodies, basic software and materials research, development of advanced robotic construction of e.g. provisioned lunar bases for humans to use, development of long baseline telescopes using self-organizing satellites/probes for high resolution acquisition, etc.
In other words, space is big and there are fabulous resources as well as fabulous threats in it. Probably a lot of exploiting it will become easier as technology advances. But some things just have to be done now, and one is finding objects that could hit us and building a capability to do something about it. Not just earth-based telescopes but also send an army of probes throughout the near and far solar system along Martin Lo's gravitational superhighway i.e. the low energy tubelike paths he's discovered threading the entire system. Unless we send probes out there now we could end up looking at something a lot worse than a Y2K problem.
Anyway it seems like a very tangible goal that can focus all kinds of private and governmental activities around the world, and could help drive related developments as well in a much healthier and interesting way than the current one upsmanship. Also a country can participate without necessarily needing to be able to launch icbms.