- "Second strike capability helps prevent nuclear war. Effective first strikes are what's destabilizing." I don't disagree! - "You need one that's already goi

- "Second strike capability helps prevent nuclear war. Effective first strikes are what's destabilizing." I don't disagree! - "You need one that's already going to pass nearby." There's a very large number of these already, within a small delta-v of Earth. We don't know where they are yet (it was a show-stopping issue with NASA's Constellation (?) program, when they wanted to demonstrate capturing an asteroid, but couldn't find one), but that's going to rapidly change. - "and during that time your enemy can send their own nuke and nudge it away" That's pretty useful: that brings it to a point where the defender has to invest an amount of resources comparable to the attacker. That's a win for the economically stronger country. If the difference grows large enough, they can simply overwhelm them with numbers. That's even before opening the technological possibilities of stealth asteroids.