One of the most harrowing insights into the psychology of genocide and the men who torture and kill, The Act of Killing reveals the long-term consequences of the Indonesian coup in which General Suharto backed by the West committed genocide when he overthrew democratically elected Sukarno in 1965; a genocide for which the perpetrators have never been held to account. We watch these men who got away with mass murder, pontificating over the justifications for their actions and the glory of victory they appear to feel, while brushing off the nightmares and espousing twisted values. But despite that, watching the interviews and you can't help but be reminded of the humanity of these people not in the sense of higher values, but rather in the fallibility they demonstrate. They are deluded, superficial, flawed but there is nothing overtly "evil" about them, as if they too are somehow products of the same kind of bureaucratic system which allowed the Nazis to carry out the Holocaust with such cold and calculated precision. Perhaps The Act of Killing shows the perpetrators as dehumanized as their victims they might still be alive, but they have in a sense become simulacras of human beings. They are both agents and victims of a higher, ideological destructive force. Few documentaries offer such a powerful, mesmerising insight into the mindset of those who kill on orders and appear to relish doing so without for one moment considering their acts as wrong. Which documentaries have you seen which have radically changed the way you view the world? Feel free to share your favourites in the comments below.