What is referred to as the first link in the chain of events that may lead to mission failure?

The term that best describes the first link in the chain of events that may lead to mission failure is the root cause. A root cause represents the underlying issue or fundamental reason that initiates a series of events or factors resulting in an adverse outcome. Identifying the root cause is crucial in operational risk management because it allows for targeted interventions, preventing similar events from recurring and effectively enhancing mission success.

In the context of risk management, understanding the root cause helps teams analyze incidents and implement solutions that address the problem at its source rather than just treating symptoms. This aligns with the ORM approach, which emphasizes proactive identification and mitigation of risks to promote operational excellence and safety.