Board Thread:Warhammer 40k General Discussion/@comment-24332685-20140111015135/@comment-24944355-20140729060012

The Chaos gods are bound to the warp and can usually touch the mortal world with a fraction of their power. The Emperor can't use the bulk of his power as to do so would destroy his body and send his spirit to the warp and he's not quite ready to go there yet. As the Emperor's still bound to the mortal world the chaos gods can only use a fraction of their power against him directly so the balance is maintained. As for the balance staying indefinitely.......that is not certain. All that you need to do is shake up ALL the factions and settle at a NEW balance and the war would continue.