[Trapped Behind Enemy Lines]

What about intercepting an asteroid and destroying it in space before it collides with the earth.

[RayChuang88]

Interestingly, it was discovered you didn't need to completely destroy the asteroid to change its potential collision course with Earth. They could have used a relatively low yield (around 25-30 kT) nuclear bomb to "nudge" the trajectory to completely missing the Earth if the bomb was detonated on the asteroid when the object was still far away.

[Gen.Blather]

“What about intercepting an asteroid and destroying it in space before it collides with the earth.”

We no longer possess a rocket with sufficient umph to get out far enough. Also, the thing that makes them so useful for destroying things is the atmosphere. With only vacuum you’d actually have to dig a hole in the asteroid. Then, you’d need a big enough nuke to blow the debris really far away or it would all hit in roughly the same spot anyway. X billion tons of rock hitting in lots of places will be just as bad or worse than the same x billion tons hitting in one spot. (Also, I think Bruce Willis is too old to pull this off. As are all the other “action” stars. So, we have nobody to do it.)