Existing cloud systems lack robust mechanisms to monitor compliance of services with security and performance policies under changing contexts, and to ensure uninterrupted operation in case of failures. On the other hand, microservices-based cloud system architectures that have become indispensable for defense applications require systematic monitoring of service operations to satisfy their resiliency and antifragility goals. In this work we propose a unified model for enforcing security and performance requirements of mission-critical cloud systems even in the presence of anomalous behavior/attacks and failure of services. The model allows for proactive mitigation of threats and failures in cloud-based systems through active monitoring of the performance and behavior of services, promising achievement of resiliency and antifragility under various failures and attacks. It also provides secure dissemination of data between services to ensure end-to-end secure operation of critical missions.