Hubs for economic activity and cultural exchange, cities serve a vital role beyond state actors in enhancing multiple dimensions of security. Diplomacy conducted by cities has grown with their scale and influence, making them increasingly central players in their own right in addressing international terrorism issues, cyber threats, and urbanization challenges. Cities are also significant sources of soft power - they facilitate dialogue and cultural exchange leading to economic partnerships that bridge divides and enhance stability, security, and prosperity. Calling attention to NATO’s southern flank, how can we engage with cities in the Mediterranean basin as gateways to the MENA region? How can investments in smart city technologies and sustainable infrastructure enhance urban resilience? In this keynote, T.H. Rui Moreira, Mayor of Porto, will address the exchanges necessary for European cities to emerge as models, contributing to trust-building between nations, and fostering mutual understanding and cooperation to address national and international security challenges.