Hello! You asked why it is symbolically important that Victor and Thomas are no longer friends:
1) Through Victor and Thomas' splintered past and present bonhomie (good-natured friendliness), Alexie highlights the complexity of Native relationships in the modern age. He shows us that dysfunctional relationships will never really mar the power of Indian tradition nor the pride of centuries of Indian identity. Thomas' penchant for story-telling filled with visions, prophecies, and quiet wisdom is just what Victor needs; it is his heritage. This remembrance of a time when Indians were independent and victorious is a vehicle for healing. Alexie shows us that tradition and heritage can wield its power regardless of the strength of any relationship.
2) Victor and Thomas' complex relationship highlights the struggle of Native Americans to meaningfully integrate their history into the modern landscape of their lives.
"You know," Thomas said. "It's strange how us Indians celebrate the Fourth of July. It ain't like it was our independence everybody was fighting for."
When Victor finds himself without means to make the necessary arrangements after his father's death, he has to rely on Thomas. He doesn't really want to listen to Thomas' stories; he is embarrassed by them and doesn't think that their shared warrior past holds any relevance to his present struggles. However, along with the tribal council's help of a hundred dollars and Thomas' financial assistance, Victor comes to realize that his 'sudden need for tradition' is all that stands between him and despair. Thomas and Victor's dysfunctional relationship highlights Victor's struggle with both his Indian identity and his identity as his father's son. It is Thomas' story-telling that aids Victor in making sense of who he is.
"...For a long time I was mad because I thought my dreams had lied to me. But they didn't. Your dad was my vision. "Take care of each other is what my dreams were saying."Take care of each other."
Through powerful Native American traditions and the heritage of story-telling, both Thomas and Victor's father enable Victor's emotional and psychological healing. Alexie shows us that tribal identity is not dependent on relationships alone; it is sustained by a powerful way of life that has endured through generations. Not even broken relationships can alter its significance and value.
Thanks for the question!