Let's say someone was forced into making an oath on the Quran to vote for the incumbent government upon becoming a citizen of that country. The person could not become a citizen without making this oath, so they're coerced into doing so. However, the person might not think that it's fair to vote for the government and the oath itself is legally dishonest.
So, what kind of sin would happen to a person who keeps to that oath? Is it fine for them to break it or must they keep it?