

Are right wing people right to seek a unified culture so that people would be willing to stand together with their peers?
Or is the left wing approach the answer where everybody but fascists is supported and the right wing people have to be convinced to join?

Yes. It’s the underlying problem. Even your summary is a valid question. People standing together means everybody has to be part of the in-group, or if there are various groups, they still have to find a common social contract. Otherwise somebody will use the situation for their benefit.