The political structure of modern countries includes a central government that exercises complete political, military, and economic control of its territory. Modern countries are considered what kind of organization?

The kind of organization, the modern countries are considered is:

State.

Explanation:

State:

In political terms, state is such a way in which a country or nation and its departments are working under an elected one government.

The word state is derived from Latin word "Status" that means condition of a country. In state, a central government runs all the institutions of the country through its members. Examples of state include the United States of America, India etc.