What aspect of command authority is often subject to negotiation among participating nations?

Operational control (OPCON) is a key aspect of command authority that often requires negotiation among participating nations in a coalition or joint operation. This is because OPCON involves the authority to direct forces assigned to a commander and implies the ability to make decisions regarding operational execution, which can vary significantly based on national policies, military cultures, and the strategic objectives of each nation involved.

In multinational operations, different countries may have their own command structures and operational procedures, necessitating discussions to determine how to integrate their forces effectively. Negotiation is crucial to ensure that all participating nations agree on how command authority will be exercised, which can directly impact the commander's ability to conduct operations.

While other aspects, such as coordination of intelligence, communication channels, and resource allocation, are also important in multinational operations, they typically do not carry the same level of negotiation regarding authority. Coordination and resource allocation may require cooperation and agreement, but they do not involve the same level of command authority as OPCON does. Thus, the nature of OPCON makes it particularly subject to negotiation among nations involved in a joint operation.