Effective Computer Network Defense requires close cooperation and collaboration between government and industry, science and education, national and international efforts. The Netherlands offers a concrete example of a successful public-private partnership aimed at improving overall cyber security for its society in general, including government, industry, and citizens. This requires more that a mere national cyber security strategy. Mutual trust between parties and close international cooperation and collaboration are essential. The Dutch approach has been successful so far, but it needs the constant attention and focus of all parties involved. The lessons learned from this approach can help build NATO's non-traditional networks and enhance its overall cyber defense posture through cooperation with partner countries, organizations, and commercial entities.