In Protestant Christianity, Neo-orthodoxy or Neoorthodoxy, also known as crisis theology and dialectical theology, was a theological movement developed in the aftermath of the First World War. The movement was largely a reaction against doctrines of 19th-century liberal theology, and a reevaluation of the teachings of the Reformation. Karl Barth is the leading figure associated with the movement. In the United States, Reinhold Niebuhr was a leading proponent of neo-orthodoxy. It is unrelated to Eastern Orthodoxy.