All US military services are directed to be integrated, interoperable, and what else?

The correct answer is interdependent, which reflects the necessity for all branches of the US military to work together in a cohesive manner. This means that each service branch must rely on one another's capabilities and strengths to operate effectively as a unified force. Interdependence is crucial in modern military operations, where joint task forces often combine elements from the Army, Navy, Air Force, and Marines to achieve common objectives.

This collaboration enhances efficiency and effectiveness during missions, as various units bring distinct skills, technologies, and resources to the table. Integration and interoperability are fundamental principles that aim to ensure services can communicate and function together, while interdependence emphasizes the relational dynamic between these forces, recognizing that no single service can accomplish complex missions alone.

Contextually, the other choices do not fully capture the essence of military operation and strategy. The idea of being independent suggests isolation, which goes against the principles of joint force operations. Supplemental implies an auxiliary role rather than a core part of a collaborative effort. Collaborative is a step towards cooperation but does not convey the systematic and mutual reliance that interdependence implies. Thus, interdependent accurately encapsulates the goal of operational synergy within the US military branches.