Conditional policies can be defined that change based on security measurements of network endpoints. In an example embodiment, a network traffic monitoring system can monitor network flows between the endpoints and quantify how secure those endpoints are based on analysis of the network flows and other data. A conditional policy may be created that establishes one or more first connectivity policies for handling a packet when a security measurement of an endpoint is a first value or first range values, and one or more second connectivity policies for handling the packet. The connectivity policies may include permitting connectivity, denying connectivity, redirecting the packet using a specific route, or other network action. When the network traffic monitoring system detects a change to the security measurement of the endpoint, one or more applicable policies can be determined and the system can update policy data for the network to enforce the policies.