Irredentism nationalism primarily aims to:

Irredentism nationalism is a political and cultural concept that seeks to unite groups of the same national identity who may be divided by international borders. This form of nationalism aims to reclaim and incorporate territories that are believed to belong to the nation based on historical, ethnic, or cultural affiliations. Therefore, the focus is on connecting the national segments that are dispersed across neighboring countries, which often leads to calls for territorial claims or adjustments to national boundaries to reflect these connections.

This concept is significant in understanding various geopolitical conflicts and movements, as it highlights the aspirations of communities or nations to assert their identity and rights over land they historically or culturally identify with, even if that land lies outside the current political borders. The other choices do not capture the essence of irredentism nationalism, as they focus on distinct areas like rights, environmental concerns, or cultural processes that do not pertain to the fundamental aim of uniting divided national segments.