There's usually a conflict going on somewhere. Wherever and whatever the current conflict is, it is typically accompanied by a chorus of voices saying this is what we should focus our defence posture on. Until the next and different conflict happens and the chorus shifts accordingly. Question is how and where can the UK best contribute. Maybe a focused contribution to central Europe, but others are best placed to shoulder the main burden on that and the likes of Poland seem to be stepping up to the plate accordingly. UK best focus on other strengths and domains, as others have mentioned.