That all sounds a bit mixed up to me. She had the legal status of being a British citizen, so previously was; but then had that status withdrawn, so now isn't. Nobody is denying anything. Being a British citizen is purely a legal position, not some unchanging or unchangeable timeless fact.
I guess the point is that it creates a two-tier system of citizenship; for some, it's precarious - it can be removed.
Which, on the face of it, does sound a bit iffy, especially in cases where people haven't chosen to be (or even know they are) dual citizens, and particularly where the effect might be to leave them
de facto (if not
de jure) stateless. (Though, let's be honest, does anyone really believe that she'd not have gone if she'd understood she would be giving up British citizenship?)
Of course, the obvious argument is 'don't become a terrorist, then', but that doesn't really address all the issues.
First, the scope of the discretion it gives the HS (and the possibility they'll use if for their own political purposes); secondly, the lack of transparency (of the decision and the oversight of it), though most people realise the need to protect sensitive intelligence; thirdly, scope creep - the possibility that the powers will eventually be used for wider purposes (albeit there's no evidence that's occurred to date); fourthly, the social message it sends about belonging; fifthly, the idea that the UK owes the rest of the world that it will deal with terrorists that have been created here; and, finally, the sort of unjust situation it creates - where someone who left a a child is rotting in custody with no prospect of a trial. (Others are also concerned it was applied in a discriminatory or an unlawful way in Begum's case, though there's no evidence of those things.)
I don't think anyone would suggest the current position is the perfect solution. But, what would be? Extreme cases like this don't lead to good laws.
One argument is that such individuals should be allowed to return to the UK. The trouble with that is that, once back, there's insufficient legal mechanisms or practical possibilities to imprison then for any significant time, or otherwise control, or monitor them, such that they could commit atrocities here (and little evidence that they want to be rehabilitated or that deradicalisation works).
So it comes back to the assessment of the risk they pose, which will typically be based on intelligence to which we can't be party. For any individual the government seeks to strip of their citizenship this could range from the dodgy end of the spectrum e.g. obtained trough torture by foreign regimes; or be reliable e.g. an eyewitness account from an undercover officer, or telephone interception; or a mixture, with or without intelligence 'spin' (politically motivated or otherwise). One thing's for sure, none of us here have any idea what the intelligence says about the risk she poses. (Part of that assessment to weigh the risk of all these people being left in one place ready to be liberated if things go south.)
Also, whilst we might have sympathy for the individual, who could be a victim in their own right (especially if young), that doesn't necessarily means there's any less risk. (Which is what we should be looking at, rather than punishment (where mitigation would be more relevant).)
And where should the line be, anyway? A 10% chance of them killing one person? A 60% chance of then killing 30? That they inspire others? Or radicalised them? That they become a rallying point for fellow travellers?
I'd prefer that she be tried and serve any sentence locally.
