A basic for any operation is to know your enemy. It is foolish to act without knowing where you are and what the defensive reaction might be. It might even be better to cancel the proposed operation if your enemy is too strong for you or the outcome might not be worth the risk.
Here's a story of four of the luckiest men alive. Stupid, but certainly lucky:
Know Your Enemy
What kind of fool would, on a whim, kill a man's dog? Why would you simply stop on the road, go behind a person's house and shoot a pet? Is this a thrill? Is there any justification?
To do it at the house of a Navy SEAL, however, is a big mistake. To survive it? That's being the luckiest guys on the planet. Not that they deserve to be, but they are.