Generally, a superpower
imperialism
Imperialism
People of one nation who are citizens of another nation are called aliens.
I believe the money called to pay to the conquering nation is called a tribute.
I believe the money called to pay to the conquering nation is called a tribute.
A country controlled by a stronger power is known as a protectorate or dependent territory. In this situation, the more powerful nation has significant influence over the policies and affairs of the smaller country.
Colonization
Lands that are controlled by another nation are called territories.
This is called imperialism. Imperialism occurs when a stronger nation extends its power and influence over a weaker nation, often taking control of its political, economic, and social aspects.
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After fighting the most powerful nation on earth for over a decade, the NVA was by far the most hardened Army in SE Asia.
Try "mandate". It could also be a colony, or it could be a protectorate, or could be simply an invaded country depending on the context.