I think you'll find the correct response is in the reply from HZ123
It's all to do with auditing ..... the UK don't audit the security regime at Geneva/Hamburg/Moscow/Jakarta etc so have no idea if it's excellent/poor or whatever.....
Given that auditing means "testing" that there's a written spec that is adequate and that the actual practice used means the written spec is adhered to the end result is that all security elsewhere is treated by the DfT as "unknown".
I suppose it really raises the question "is that the correct test to apply?".
If the DfT are correct then how can other security regimes accept on faith the adequecy of annothers effectiveness??