And they have to assume you will assume this, so they would expect your silos will already be emptied in a retaliatory strike. Of course you have to trust early-warning systems and the ability to react decisively and quickly.

The B part of ICBM means ballistic, and they are. Thus you can get a useful approximation of where it’s going to land based on the initial trajectory.

By useful I mean you can do significantly better than saying if it’s targeting the middle of the US, east, or west coast. Though it’s quite a large area.

> you can get a useful approximation of where it’s going to land based on the initial trajectory

If you’re doing a first strike and aren’t a moron, you conventionally strike the early-warning radars first. Ideally in a plausibly-deniable way.

First strike detection isn’t limited to early warning radar or ground based systems except in the very early days of the Cold War.

There’s no plausibility deniable way to take these systems down in practice.