The case studies of the project TERRA-RES (Territorial Exaptive Resilience along EU Eastern Borders) were purposively selected to represent a diverse range of border regions in the EU's eastern borderlands, each facing unique challenges and opportunities in the context of geopolitical changes, environmental crises, and social and economic disruptions. The selection criteria included:

1. Inclusion of at least one Polish external border region
2. Representation of multiple affected countries
3. Heterogeneity in the development levels of the regions
4. Inclusion of at least one region bordering Ukraine, one bordering Russia, and one bordering another post-Soviet country (Belarus or Moldova)

Based on these criteria, five case study regions were selected: 

1. Maramureș County in Romania, 
2. Lapland Region in Finland, 
3. Szabolcs-Szatmár-Bereg County in Hungary, 
4. Olsztyn Region in Poland, and 
5. Vilnius County in Lithuania. 

This diverse selection allows for a comprehensive analysis of how border regions with different characteristics and capacities respond to and recover from shocks and disruptions.