In the blood feud, the orientation is not to the future, as in war, but to the past. In the feud you are avenging yourself on your enemy for something that he did in the past. Al Qaeda justified the attack on New York and Washington as revenge against the USA for having defiled the sacred soil of Saudi Arabia by its military presence during the First Gulf War. In the attack on London, the English were being punished for their involvement in Iraq and Afghanistan.
In the blood feud, unlike war, you have no interest in bringing your enemy to his knees. You are not looking for your enemy to surrender to you; you are simply interested in killing some of his people in revenge for past injuries, real or imaginary -- nor does it matter in the least whether the people you kill today were the ones guilty of the past injuries that you claim to be avenging. In a blood feud, every member of the enemy tribe is a perfectly valid target for revenge. What is important is that some of their guys must be killed -- not necessarily anyone of any standing in their community. Just kill someone on the other side, and you have done what the logic of the blood feud commands you to do.
In the blood feud there is no concept of decisive victory because there is no desire to end the blood feud. Rather the blood feud functions as a permanent "ethical" institution -- it is the way of life for those who participate in it; it is how they keep score and how they maintain their own rights and privileges. You don't feud to win, you feud to keep your enemy from winning -- and that is why the anthropologist of the Bedouin feud, Emrys Peters, has written the disturbing words: The feud is eternal.