Unless you regard something like “Iron Man” as a film about Afghanistan, the movies inspired by America’s contemporary wars have consistently been box-office flops. Even “The Hurt Locker” grossed only $16 million in theaters. Video games that evoke our current conflicts, on the other hand, are blockbusters — during the past three years, they have become the most popular fictional depictions of America’s current wars. Last year’s best-selling game was Call of Duty: Modern Warfare 2, which opens in Afghanistan; it was a sequel to a multimillion-selling 2007 game that features an American invasion of a nameless Middle Eastern country. Modern Warfare 2 has made “Avatar”-like profits for its studio, Activision. On the day the game was published in November, it sold nearly five million copies in North America and Britain, racking up $310 million in sales in 24 hours. By January of this year, the game’s worldwide sales added up to $1 billion.