The situation to date seems to be that someone has decided that the Queen's troops, wearing their official uniform can't be in some parts of the UK as they represesnt some sort of 'threat', rather than the forces of law and order. I suppose that they might be targets of some terrorist attack or that they might cause an attack to take place.
But how can a diverted flight be a threat? The threat to security at BHX would come from regular military movements that could be monitored by an extremist group and who could then act on any pattern setting they observed, whether that be to target the ac, either on app / dep or to target the personnel it was carrying as they were in the building.
To target a diverted flight in an opportunistic attack would mean a security breach from someone with inside knowledge of the intended military movements and that BHX is currently being dicked by an extremist terrorist cell, actively looking for a target of opportunity. And if that is the case, then quite frankly, the head of security at BHX has much bigger problems than a few squaddies in deserts to contend with.
Sounds like a load of politically correct tosh and nonsense dressed up in the thin veneer of security. Like so much else this Govt has done.