There is little doubt that Earth-orbit-crossing asteroids represent a danger to our world and its inhabitants. Moreover, the impact of even a rather small object would have a distressing effect on humanity. Last month the technologies and techniques to defend earth from planet-busting giant rocks were tackled at The Planetary Defense Conference: Protecting Earth from Asteroids. Experts have repeatedly raised a cautionary flag that more attention should be paid to the near-earth object hazards, but trying to find a welcome mat at the doorstep of any "take charge" agency in the United States or elsewhere has been tough to do.
Currently most of the effort seems to be at detection to proactively determine the problem and once it is characterized, solutions could be creatively developed. Seems like a wise approach considering how devastating one of these huge rocks could be if they hit earth.
USA Today March 12, 2004