Asset and Vantage

Asset noun - A person who tries secretly to obtain information for one country in the territory of another usually unfriendly country.

Vantage and asset are semantically related In some cases you can replace term "Vantage" with "Asset", this nouns are similar.

Vantage noun - The quality of having a superior or more favorable position.

Asset and vantage are semantically related in advantage topic. Sometimes you can use "Asset" instead a noun "Vantage".