Points by correct country. And relative distance to target
I think being in the correct country is more important than the actual distance to the target. My suggestion is, if you hit the correct country, you will receive points by relative distance to the target within the country. If you missed the country completely, the points will be counted by distance.
I realize it is a very difficult thing to implement, and a lot of optimization will have to be worked on. But at a later stage of the game, I think it might be a good thing to add.