“NATO is the most successful defence alliance in modern history.” While some may argue that this is a superficial cliché and that the Alliance is fast becoming irrelevant, others believe that this is a truthful statement reflecting the Alliance’s well-deserved prominent place, not only in the annals of history but also in today’s and, most probably, tomorrow’s security environment. I personally subscribe to the latter school of thought. Why and how has NATO been successful? Is it due to its robust assets and capabilities? Or due to its firm commitment to its most fundamental mission- collective defence, i.e., its musketeer philosophy: “One for all, all for one?” Could it be its resolve not to compromise the unwavering principles of indivisibility of security, allied solidarity and cohesion which cement the Allies together? Is it its consensual decision-making that ensures unity for a robust and credible Alliance Or is it NATO’s role as the embodiment of the transatlantic link that binds Europe and North America? Or does NATO owe its success to its readiness, willingness and ability to adapt itself to both the slowly evolving international environment and the rapid outbreak of conflicts? I believe that these questions are self-explanatory as to how and why NATO is a success story. The next relevant question, then, is “How can NATO maintain its relevance and success?”