The Shield-Wall divides the world of Mortal Engines in two and symbolizes the difference between the aggressive colonizers in London and the more peaceful Anti-Traction League. The Wall symbolizes stability and the defensive nature of the Anti-Traction League. Unlike London and other predator cities, the members of the Anti-Traction League don’t need to “eat” others to survive. This doesn’t mean that the League is full of pacificists—spies like Anna Fang are willing to use violent tactics, and settlements like Batmunkh Gompa have extensive fleets of combat airships. Nevertheless, the Wall suggests that these settlements would prefer to live in peace and have only adapted to avoid being destroyed by big cities like London. While London attempts to destroy the Shield-Wall and seems to have exactly the right weapon to do it with MEDUSA, ultimately this effort fails and London ends up destroying itself instead. This suggests that the more sustainable, peaceful lifestyle that the Shield-Wall represents is ultimately more durable than the fast and dangerous lifestyle of London.
Shield-Wall Quotes in Mortal Engines
“Nor will we have to go chasing after scraps like Salthook,” Crome continued. “In another week London will be within range of Batmunkh Gompa, the Shield-Wall. For a thousand years the Anti-Traction League has cowered behind it, holding out against the tide of history. MEDUSA will destroy it at a single stroke.”