The West has been destroying itself lately, imagine if the Soviets could take advantage of it
While I feel like you could maybe detonate one on land, I’m not sure you could “fire” a missile without total control of all sorts of infrastructure, like all sorts of networking, crypto, spy satellites, and maybe even troops in each silo. Even then I think that the early warning systems (afaik they can know about a launch but not necessarily the target) of other nation states would make it a risk to fire one even within the US because it would risk retaliation and mutually assured destruction