Final answer:
Sovereignty is key for a dependent nation to maintain strength as it ensures independence and the ability to govern without external interference.
Step-by-step explanation:
For a dependent nation to project and maintain political, economic, and military strength, the element displayed is sovereignty. Sovereignty is the full right and power of a governing body over itself, without any interference from outside sources or bodies. It is essential for a state to have sovereignty to pursue policies and actions that it deems to be in its own national interest and to manage international relations effectively. Hence, sovereignty enables a state to act independently and protects its autonomy in the international community.
Related concepts include: states exercising power by recognizing another state's sovereignty; international law resting on the principle of state sovereignty; and the concept of a sphere of influence, where a foreign power may have control but does not impede the sovereignty of the influenced state. Ultimately, independence and sovereignty are paramount for a nation as it formulates domestic and foreign policies.