The Tunnels of Cu Chi is a book written by Tom Mangold & John Penycate in 1985 focusing on a specific aspect of the Vietnam war which lead the U.S. Army to loose it. The technological and human asymmetry was nevertheless striking but such subterranean complexes allowed the Viet Cong to organize a strong resistance against the invading army. The ability for the earth to change its solidity characteristics was fundamental in the elaboration of a physical mean of defense:

The soil of Cu Chi is a mixture of sand and earth. During the rainy season it is soft like sugar, during the dry season as hard as rock. […] Such soil could stand the weight of a tank.

The U.S. Army volunteers who were exploring the discovered tunnels were named Rats. This name is not innocent as, for their psychological and physical survival they had to develop what Gilles…