Who developed this defensive plan in the 1880s that has Fort de Cindey as one of its three principal fortified regions?
Fort de Cindey: The Fort de Cindey (Swiss designation A155) is a component of Fortress Saint-Maurice, which is in turn one of the three principal fortified regions of the National Redoubt of Switzerland. National Redoubt (Switzerland): The Swiss National Redoubt (German: "Schweizer Reduit" ; French: "Réduit suisse" ; Italian: "Ridotto nazionale" ; Romansh: "Reduit nazional" ) was a defensive plan developed by the Swiss government beginning in the 1880s to respond to foreign invasion.
the Swiss government