Yes, there is a difference between the nationalism of those who already have a nation-state, and seek to assert its inherent superiority over others, and the nationalism of those who seek a nation-state of their own. I am often confronted with this over the nationalism of the Celtic "fringes", especially Scotland, with which the left tends to sympathise, vis a vis English supremacist nationalism, which the left tends to abhor. My answer is that it is a fallacy of equivocation to compare the two: The nationalism of Brexit and the nationalism of independence movements are two only distantly related sympathies which unfortunately share a name. There is an obvious contrast between the nationalism of an oppressed people and the nationalism of their oppressor; between a nation seeking freedom and a nation denying freedom.

My personal view of the nation-state is that it was an inherently liberal idea: That all white males would live together under a system of common laws and governance in which all shared certain common rights as citizens. It was a notion that set Enlightenment societies apart from feudalism, and as such always sat uncomfortably in the same boat as a monarchy. The left has tended to reject the notion that this system enfolds only white males, whereas the right are today seeking a regression to precisely that restriction.

But more than anything, the cynic in me thinks that liberals have tended to shy away from nationalism since it proved such a murderous influence in the 19th and 20th Centuries; the right has tended ever more to embrace the nation as a right-wing property for precisely the same reason. The Enlightenment provided liberal ideas which seemed good at the time; conservatives start to claim they were their ideas all along once they've been proven not to work.