11. Poland and Lithuania
Historical grievances—most notably border disputes—strained Poland-Lithuania ties. Following 20th-century upheavals, both joined the EU and NATO, cementing collaboration on economic, security, and cultural fronts. In 2024, Poland and Lithuania sought EU and NATO assistance to bolster their shared border defense, emphasizing the importance of safeguarding the eastern flank of the EU and NATO. This joint initiative underscores their commitment to regional security and mutual support (euronews.com).
