'British-born', 'home-grown', 'self-radicalised' etc. are disgustingly primitive and self-serving expressions of the so-called 'liberal values'.
The fact is, that whether foreign-born or not, all, I repeat ALL terrorists, whether a whole cell, or a 'lone wolf' can trace their ancestry to a certain part of the world, where a particular religious ideology or dogma is prevalent.
Had those people, or their parents and grandparents not been allowed to immigrate en masse, we wouldn't face the scourge of islamic terrorism we are facing today.
It is that simple.