1) Will your friend introduce you to his friends, insisting that they be your friends too?
2) Will you take on any enemy of your friends, as your own enemy for that sole reason alone?
4) Will you instantly open your heart to embrace a new friend for the sole reason that that new friend is also your enemy's enemy?
No one likes these laws. No one can prove them wrong.
Most don't like such analysis. Everyone must do it.