Which term refers to ultimate governing authority and the power to decide domestic and foreign policies within its territory?

Sovereignty refers to the ultimate governing authority that a state holds over its territory. This concept encompasses the power to make decisions regarding both domestic policies, such as lawmaking and governance, and foreign policies, including diplomatic relations and national security. A sovereign state has the independence to operate without interference from outside entities and possesses complete control over its internal and external affairs.

In contrast, autocracy, federalism, and dictatorship describe specific forms or structures of governance rather than the broad, essential concept of sovereign authority. Autocracy focuses on a system where power is concentrated in the hands of a single ruler or a small group, whereas federalism refers to a system of governance in which power is divided between a central authority and smaller political units, like states. Dictatorship is a form of governance where a single leader holds significant or total power, often without democratic processes, but it does not inherently include the concept of sovereignty. Thus, sovereignty remains the most accurate term to represent ultimate governing authority and the capability to decide a nation's policies.