Area of country that is controlled to some extent but not governed by a foreign power

Sphere of Influence

Explanation:

In order to know more about the answer, let's dig deeper on what the "sphere of influence" means.

Sphere of Influence is also known as zone of influence. This allows an external group to have power over a country or territory, though not formally.

One example of this is the country of China. It became a sphere of influence in the late 19th and early 20th century when it became a subsidiary of the state of France, Britain, Germany and Russia. This historical event was extreme because it made China a "de facto colony," meaning their sovereignty was controlled by the aforementioned countries without international recognition.

Owing to the existence of sphere of influence, many countries in the world share the same culture and tradition.