Why tunnels and hardened shelters matter again

Drones in Ukraine and in the War with Iran have made the surface of the earth a contested space. The U.S. has discovered that 1) air superiority and missile defense systems (THAAD, Patriot batteries) designed to counter tens or hundreds of aircraft and missiles is insufficient against asymmetric attacks of thousands of drones. And that 2) undefended high value fixed civilian infrastructure – oil tankers, data centers, desalination plants, oil refineries, energy nodes, factories, et al -are all at risk.