As much as I can be simpathetic to groups and people closely related to their tradition, language, territory and although acknowledging that those factors need to be permanently defended in order to remain alive, I cannot support nationalism.
Because, eventually, nationalism is against the others. And nationalists tend to use the defense of their own space to justify aggressivenes and non respect of others’ opinions and rights.
I found a quote from Albert Einstein: “Nationalism is an infantile disease. It is the measles of mankind.”