Final answer:
National security now includes economic, energy, and environmental security to protect against a broad range of threats from both state and non-state actors, and possibly even natural disasters.
Step-by-step explanation:
National security has evolved from being solely about military power to include a wide spectrum of aspects such as economic security, energy security, and environmental security. To ensure national security, a country must protect against a variety of threats that not only come from nation-states but also from non-state actors like violent non-state actors (e.g., al Qaeda), narcotics cartels, multinational corporations, and non-governmental organizations. Additionally, certain experts consider natural disasters and adverse environmental events as part of national security concerns.
Policies and measures to safeguard national security are extensive and may include intelligence gathering, military readiness, strengthening cybersecurity, and ensuring critical infrastructure security. These strategies are vital for maintaining the sovereignty and safety of a nation in the face of both traditional and non-traditional challenges.