Cats fighting

All the cats in our street have a pecking order which they must observe. As humans we can try and intervene when we see our cat scrapping with another, but ultimately the scenario must be played out until the order is established.
Still, it made me feel bad when I opened the door yesterday to let the cat out and one of her targets was sitting right outside. Our cat went for the other one without delay. I tried to break it up, but realised that as soon as I close the door they'll be back at it again.