1. Spies (especially if they have a French accent)
2. Members of any Armed Force (including the IDF)
@Ambassador, are you sure you don't mean mercerenaries? The volunteer soldiers who form part of the British services won't have joined up just to go into conflict. Most of them will have been in the TA for years and be fully trained. They are called up when needed and their employers give them leave to join their units.
All members of the British Forces join up knowing they will have to fight for their country at some stage, that's why they are all heroes. Even years ago when we weren't involved big time in the ME there was always NI to sort out. My ex husband served in NI on a number of occasions and we had friends killed there. It would have saved me thousands in divorce costs if it had been him, but that's another story.