Having divested almost completely from its colonial empire, having tolerance for protests and almoat all speech, why should the UK be afraid of (non Soviet) missile attacck?
Surely it's done what it could to be as accomodating as possible.
Nowadays an attack can come from terrorists, so it doesn't even have to be some rogue state. As drones are becoming cheaper and more accurate it doesn't take state like resources to do real nasty damage anymore.
But it can also be rogue/failed states (no shortage of those), and it can also be Russia.
Britain was already a target of major terror attacks.
Iron Dome is a symbol of failed foreign and defence policies. 7th of October showed that defence and appeasement does not work with genocidal jihadists. The source of attacks needs to be destroyed and building forever growing protection systems is not a solution.
Surely it's done what it could to be as accomodating as possible.