Whilst I'm not in the industry (and therefore can't speak with any authority), I will say anecdotally that having a degree simply isn't a guarantee for employment anymore, let alone relevant employment. What I advise you do is do a little bit of research - find the people who have the kind of job you're interested in and see what steps they took to being where they are. What I can almost certainly tell you is that none of them will say "I got my job as a [insert relevant IR profession here] because I studied IR at [insert university] and am quite articulate". As somebody who studied English, I strongly suggest you shake off naive ambitions (not to put a dampener on things), just try to be realistic.
If anyone believes I am incorrect, feel free to correct my assertions.