Who benefits from Embargo and who loses?

to be honest, I don't think either of them have benefits from an embargo. The person who put the Embargo on another country doesn't have the benefit of getting supplies from that country, and the country who has an embargo put on them doesn't have the benefit of importing and exporting Goods.

social contract theory, nearly as old as philosophy itself, is the view that persons' moral and/or political obligations are dependent upon a contract or agreement among them to form the society in which they liv