I'm not sure that "conquered people still agitating as their former group, against their conquerors" qualifies as ethnonationalism. I think there have to be claims of ethnic superiority, deliberate exclusion of other ethnicities and nationalities, etc etc
In other words, a group of people whose internationally-recognised sovereignty was taken from them under threat of arms is not engaging in ethnonationalism by demanding that some portion of that sovereignty be restored. That's not the part of Nazi Germany that people object to, either.
In other words, a group of people whose internationally-recognised sovereignty was taken from them under threat of arms is not engaging in ethnonationalism by demanding that some portion of that sovereignty be restored. That's not the part of Nazi Germany that people object to, either.