English often turns to German for wholesale borrowings of words expressing not-so-simple concepts — think Schadenfreude, Weltschmerz, or Zeitgeist. Leitmotif  (or for purists, leitmotiv)fits pretty well in that category; it's a 19th century music term that has long since left the confines of Wagnerian music for any recurring theme closely associated with an idea, person, or situation.