After a week of speculation, the US Department of Justice has officially indicted Raúl Castro, the 94-year-old ex-president of Cuba. The charges relate to a 1996 incident in which the Cuban military allegedly shot down two unarmed civilian planes operated by Brothers to the Rescue. The news comes amid mounting US pressure on the ailing Cuban Republic to change its system of government after 67 years of revolutionary rule. So why did the United States act now, and what will happen next?