Until a different and more able technology emerges, I'm in favor of using and refining the technology we have. Thanks to defense contractors, star war missle defense technology and NASA scientists, we have the ability to drive something nasty into an object at great distances. And armed with the right warhead, maybe reconfigure it enough to effect a
Guy, please understand that I'm not talking politically here but am speaking purely technically as an software engineer. I have absolutely zero faith in the ability of defense contractors to make a working missile defense and equally little faith in their ability to control the path of any large body in space by means of explosions. The complexity of the required software is orders of magnitude greater than the couple of cooked demos that sort of, kind of, worked. Perhaps with a few years of sustained testing (another term for all-out war), a few of the kinks could get worked out. But systems that complex never, ever, ever work the first time in the real world. Never. Simulations help, as do war-gaming and unit tests. But the real world always throws surprises at you.
I'm in favor of researching new technologies, but I'm not willing to discard one technology before we have a working replacement in hand. We can resort to throwing soot, popcorn or fairy dust for that matter, at the problem if this doesn't pan out. ;) And speaking of defense contractors, they and their employees provide a valuable service to this country, and they, like you and me, have families to feed, so I'm in favor of providing them the work.
I'm certainly not against defense contractors, but there are far too many careerists among them who are interested in pouring money into things that just don't work (the Osprey comes to mind). I've interviewed an awful lot of engineers leaving defense contractors and have found their innovative abilities and creativity have been crushed by the job. A lot of them have a difficult time doing commercial work because their flexibility has been beaten out of them. Seems like it ought to be the other way around. It's far too easy to pour your money and manpower down a rathole. I know you don't care for welfare programs and that's just what an asteroid defense program could be. It's a way for bird colonels to stay busy when they really should just get mustered out. If you're really interested in fighting asteroids (I personally think humanity poses a great danger to humanity), then the thing to do is fund a number of small innovative groups to develop a broader range of technologies. Let that stew for a while and see what you get. Chances are that we have a much broader range of choices available to us.