Unfortunately, May's powers only permit her to revoke British citizenship for those doing something 'seriously prejudicial' to the UK's interests to those with dual nationality. This is a necessary safeguard to prevent zealous socialist ministers from cancelling the passports of UKIP members on holiday abroad. So there is no easy sanction against the sole British national jihadist training in a Pakistani terrorist training camp. For the rest, those with dual nationality, the message is simple;
- book your terrorist training package holiday in Pakistan, the Sudan or Yemen and fly out
- the Home Secretary cancels your British citizenship
- turn up at the immigration counter a month later to have your passport confiscated and be refused entry back into the UK
- be blocked from appealing to the ECHR because you're no longer a British citizen
- return to Pakistan. Get martyred by a US drone.