In the 2001 book The Unfinished Twentieth Century, author Jonathan Schell suggests that an essential feature of the twentieth century was the development of humankind's capacity for self-destruction, with the rise in many forms of "policies of extermination". Schell goes on to suggest that the world now faces a clear choice between the abolition of all nuclear weapons, and full nuclearization, as the necessary technology and materials diffuse around the globe.