Ben
Whether it's an aircraft entering UK airspace, or a target on the ground in Aghanistan, both are being targetted because they pose a threat to the UK. I can see why you would be more comfortable with the former, becuase it is more "obviously" a threat, and therefore more easily justifiable, but does that mean you would only ever want to take action when it becomes immediately necessary? Do you feel that pre-emptive action is always wrong, even if acting sooner rather than later may, in the long run, save more lives? If not always wrong, in what circumstances is it justified?
I think everyone asks these questions at some point (at least they should do), but you do need to be able to answer them and be comfortable in your own mind before you proceed. A favourite question during interviews is to ask how you might react if you were asked to bomb a school. Rest assured, if you have been told to bomb a school, that decision has been made by someone with more knowledge of the circumstances, and who is just as aware of the consequences as you are. They won't enjoy giving the order, but they do need to be able to trust you to carry it out. The system cannot operate without trust in every member of the team to do his or her duty, and if that 5% doubt might translate into refusing an order, you will not be a good part of that team. It's great that you're thinking so hard about this, but it's important to remember that now is the time to do the thinking and make firm decisions aboiut your moral viewpoint - not when you're given the order.
Warty