system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Would it be possible for another country to BUY a country in debt?
gpt
The only ways to gain control of a country is through conquest or treaty.

In a treaty, you can theoretically place a condition by which the annexing nation pays the remaining debt of the nation being annexed.

This would effectively be "buying" a nation, though it is not something that could be done without the debtor nation's consent.