"There are no permanent friends, only permanent interests."

It is not applied for any field. maybe it is right for politics, but for common friends, the saying doesn't work. Usually, I have no interests conflicts with my friends. and we often help each other when we are in trouble.

I think that's politics, but it cannot be apply to real life. I do believe that there are permanent friends because the real friends that i have now not be friend with me because of their interest because I have nothing much to give.

Hello! I don't follow who is who in your writing. Nevertheless, in general, there is something like commun reality. Shared reality. Life happens. People change their viewpoint according to their education (in general), their ability to observe and make their own conclusions and realities changes... It all depends how things are done, I would say. If no warning or prior communication and understanding of the fact of shifted realities, something like this could be resented as betreyal. In military, it would be like treason. People can feel betrayed. I would say that it would be because of lack of communication as I mention above and/or the lack of the person being betrayed to be able to understand and accept other people's reality if different than theirs. See how it could work? We're pretty much back to: Communication! It would be rather tricky if one gave allegiance. One has better determined with solid facts that the entity he gave allegiance to was in actuality the wrong one. Like, maybe, he has been tricked and discovered the truth after the fact or he didn't do a proper observation and went ahead. Now, he wants to back off because his integrity is at risk. Tricky. Hurray