Yeah exactly. Shooting hundreds of bullets with your bullets. And each bullet you need to shoot breaks into smaller bullets upon re-entry that start randomly maneuvering. Hit to kill is just not practical against a peer firing hundreds of ICBMs.

That's why I suspect the US never stopped developing nuclear tipped ABMs with the Sprint I and II programs. They just went dark. It's the only logical way to defend against the only existential threat we face, and DC is gonna be first struck so you can bet the political class is incentivized to develop this.

Why keep it secret? Well first it interferes with MAD which is very destabilizing. Also its good to hold your most important cards close to your chest. And there's the fact that the public would be uncomfortable with the idea that our plan to survive involves so much radiation being thrown around. A lot of incentive to not talk about it...