Carving up the World Again... a Wall and Not a Fence

Here, Robert Plant expresses his dismay at a world going off the tracks. The song finds him railing against, "Emperors and sultans, kings and presidents. Dictators and ambassadors engaged in our defense."

Plant described the song to The Sun as a "very quick glimpse at what we've had to do because we have no faith in mankind. We're strange animals because we can do so much good." He added: "I heard this morning that someone is intent on colonising Mars, the red planet, and yet if that's possible, how come we're not able to take in the ebb and flow of humanity, brother to brother, side by side, the different languages? We haven't got things right so people are ready to bail."

Plant takes aim at xenophobia and the refugee crisis during the song. He told The Independent: "There's progress in many areas of humanity, but it's juxtaposed with doors slamming and pain."