The interplay between cultural-artistic expressions and International Relations is rarely taken in consideration and examined; and most people do not even think about it. Still, it is way deeper than it may appear at first; and it reveals much about how a certain issue or actor is perceived, and this in turn deeply influences how we react to it.
As a matter of fact, IR essentially examines the relations of actors at the international level. Now, every relation involves a mutual interaction, which also means a reciprocal definition between the involved agents. According to the Constructivist school of IR, the way states (and other actors) define themselves and their peers shapes their mutual perception and determines the type of interaction they have.
This is why the cultural dimension of IR is so important: thanks to their immediateness and easy access, artistic expressions like novels, movies, paintings, songs, etc. can deeply influence our perception on a certain issue, state, or epoch. This is also due its very nature, art can deliver a specific message in a direct way, immortalize or denounce an event, create a myth, shape our conception of a historical moment or statesman. In other words, it is capable of building our collective memory; and this has a tremendous influence on how people and states interact with each other and react to a given event. Again, this also explains the prominent role played by art in propaganda, education, nation-building, soft power, and so on.