I think in the long run, nationalism will be seen as a stepping stone to globalism. A transitory period between between localism and globalism. The main reason being is the cultural homogenization that nationalists fear globalism will bring was already carried out by nationalism.

Dialects and local traditions were directly and indirectly destroyed through nationalism and replaced with a standardized 'national culture'. In the case of Europe, this national culture has been established for a few centuries now but it never formed in most of the non-West.

Olivier Morin in his book 'How Traditions Live and Die' cites that real traditions have a great deal of heterogeneity that varies even within a single community. Nationalistic pseudo-traditions are often standardized for millions in a way that encourages their stagnation.

'Official cultural costumes' are the best example. Many countries have these and in many cases they were recent inventions or a single traditional outfit was then expanded to be the be all and end all of that countries 'cultural clothing'.