Gog and Magog
In the Islamic apocalyptic tradition, the end of the world would be preceded by the release of Gog and Magog, whose destruction by God in a single night would usher in the Day of Resurrection. Reinterpretation did not generally continue after Classical times, but the needs of the modern world have produced a new body of apocalyptic literature in which Gog and Magog are identified as Communist Russia and China. One problem these writers have had to confront is the barrier holding Gog and Magog back, which is not to be found in the modern world: the answer varies, some writers saying that Gog and Magog were the Mongols and that the wall is now gone, others that both the wall and Gog and Magog are invisible.