The CRM (Composite Risk Management) process step that requires a cycle of two assessments is the "Develop Controls and Make Risk Decisions" step. This step involves assessing the risk, determining risk decisions, and developing the impact of those decisions. The cycle of two assessments is necessary to ensure that the benefits of completing the mission outweigh the risks of not completing it, and it allows for continuous reassessment and adjustment of the controls and risk decisions as needed.