Groups identity is fragmented precisely because of nationalism. White nationalism, black nationalism, original country nationalism of immigrants. If there hadn't been nationalism, you remove one of the major reasons for that fragmentation in the first place.

You are trying to define the existence of multiple cultures inside a nation, as a reason why a unified national identity is an issue?

You cannot remove the idea of a national identity without some way to prevent a unified group from forming in exclusion to the rest of the population, to advance their group primarily. And the word for that is nationalism.

If you are talking about national identity bereft of and independent from race or ethnicity then you are close to what I want and are maybe using the word nationalism differently from what I meant. Except I go one step above and believe in taking this to a supra national level. You clearly see benefits in dissolving ethnic/racial identification in service of a larger group viz a nation, I just believe in taking it a step further. It has nothing to do with the number of governments one wants or wanting a world government. I don't feel a need to be governed by Germany or France while at the same time I feel no problem in my money and my support going to them and in feeling kinship with them over common principles.

I think ethnicity is also not a good fit if thats what you are intending it to mean.

But actual ethnicities and races will in any case emerge in any society over the centuries. And we will need another set of wars and bloodshed to relearn the lessons of ethnic/racialism being bad again.

That's where I differ. I see absolutely no point in ethnic identity and what benefits it gives us (over its negatives). If you tell me there is a plot of land available and I get enough people to agree I'd gladly jump in with peoples of liberal capitalistic democratic mindset with absolutely zero shits given about race or ethnicity or language to form a new country. We will set a common language but its simply a matter of common standards, not some emotional or historical appeal to thousands of years ago. I'd explicitly make it clear in the founding documents we are not founded on any race or ethnicity or religion.

I don't feel nationalism. I want good public infra, more housing because it simply makes life better. For example, have you ever released anything FOSS? I haven't yet but it is my aspiration to, I don't care which country or person it helps. I will happily support liberal democratic elements whether they be Germans in Germany or blacks in America or any other group. And conversely, I would absolutely fucking hate any of my tax money supporting far right wing elements in my own country/race or otherwise. But I am not stupid enough to deny improvements in my country just to spite these retards.

Sure, I use and contribute to some; and participate in international groups.

The key part for me though is the voluntary nature. I can participate as much or as little as I like, and my motivation to participate can be entirely individualistic, and the whole thing still works (more or less).

Taxation and policing is not voluntary however; and I frequently see the proceeds going to short term initiatives, that are promoted based on how much they impact some minority group specifically.

Advancing one group in a democracy is not often even a neutral action; its entirely possible to use resources so poorly that it's harmful overall. (Both in economic terms, but also in more abstract things like public trust in policing, or tolerance of corruption)

Eg I dislike mistreatment of a person of my race or any other race but its not due to racial kinship but distaste for mistreatment in general. I would say I am very low on race, you could say even deracinated and anti national overall in my worldview.

And for me the slicing in dicing happens for non-racial axes, I don't like certain racial minorities getting some subsidies but I don't "feel it in my bones" so to speak whereas I absolutely hate in my very bones the fact that eg conservative voting provinces are getting services from my tax money. Ideally of course I'd prefer not subsidizing any racial groups. Again, the concept of a country or nation defined without race or ethnicity is much closer to what I believe in anyways, except I want it at an even large scale.