Many things can go under the radar if a commission is set up to study the possibility of an asteroid impact and what defences are available in case one comes our way. It is incredibly difficult to hit something that is coming straight at you as it only shows its front. Anyway, we already have lasers that can shoot from earth into space as shown by the video shot by the spaceshuttle.
Obviously what they want to investigate, is what to do if the Moonies start attacking after we bombed their base on the Moon with the LCROSS. The trouble is that it is everyone else who gets the brunt of the attack and the people who ordered it just go into their underground bunkers and wait until it all blows over. If there is anything left on the Earth, then they just come up and start again where they left off - with fewer people to manipulate.
On a side note, I do not have a link for this one, but a new tool for asteroid hunting has become operational in Hawaii. A telescope was teamed with a 1400 megapixel camera to track "moving objects" in the sky. Now that would be interesting to get photographs from that!