It's ot always enemy land.It can be your own realm's regions for instance.
And how do you know that those papers are authentic?
Or that the enemy scout didn't capture one of your realm's scouts, kill him, and steal *his* papers?
You can tell by beating the crap out of him. Beat the incompetent fool enough, and he'll tell the truth. After all, no one would lie and besmirch their own honor just to stop a little bit of pain, right?