In the past, Computer Network Defense (CND) intended to be minimally intrusive to the other requirements of IT development, business, and operations. This paper outlines how different security paradigms have failed to become effective defense approaches, and what the root cause of the current situation is. Based on these observations, a different point of view is proposed: acknowledging the inherent composite nature of computer systems and software. Considering the problem space from the composite point of view, the paper offers ways to leverage composition for security, and concludes with a list of recommendations.