Mahatma Gandhi once said "An eye for an eye makes the whole world blind." But the midseason finale of Fear the Walking Dead proved that it only leaves like, half the world blind.
Peace through diplomacy actually seemed within reach at the beginning of the finale. Jake hoped that the sharing of resources would allow Walker's tribe to thrive where they are and leave the ranch to Jeremiah and his people.
Part of Jake's parley required a volunteer from each side to remain as a sign of good faith. Alicia insisted on staying with Walker. Unfortunately, Madison through a huge fit and went with Troy and the militia to "rescue" Alicia. To no one's surprise, lives were lost and a full on war was declared.
Ofelia is back. Apparently she is romantically involved with Walker. She also managed to poison the ranch's militia with some anthrax. This led to zombies and more death.
Ultimately the only way Walker's hate could be satiated was for Jeremiah to die and for the ranch people to share some of their resources. So Madison asked Jeremiah to kill himself. When he refused Nick shot him in the head.
Madison gave Walker Jeremiah's head and it appears that the founder's blood was enough to bring peace. At least for now.