What are the fundamental roles of the U. S. Navy, Marine Corps, and Coast Guard in the implementation of the National Naval Strategy (NNS) ?

The naval strategy is the preparation and execution of combat at sea. Naval strategy and the associated theory of maritime strategy involves the comprehensive strategy for gaining supremacy at sea, which includes the planning and execution of operations, the action and disposition of naval units by which a leader achieves the benefit of struggling at a place accessible to himself, and the deception of the opponent. The following are the fundamental functions of the U. S. Navy, Marine Corps, and Coast Guard in the execution of the National Naval Strategy:

1. Secure strategic passage and maintain the global choice of action.

2. Extend existing and developing partnerships and alliances

3. Secure favorable defense requirements

4. guard the U. S. against direct invasion