Military systems and government agencies whose mission and functions require continued operations in wartime and whose activities can be made compatible with a deep underground environment should be designed in the future with the following premise in mind: survival from a very impressive attack is feasible at practical depths of cover.
Underground survival obviously means that the cavity containing the installation does not collapse and that no violence is done to the contents, the residents included. An impressive attack should encompass the possibility of a number of weapons of high accuracy and high yield. Practical depths of cover must be defined in terms of availability of sites, cost of construction, and operational feasibility.
Underground survival is not something that you can ensure without the proper knowledge and expertise. A lot of things should be taken into consideration and this case study is a good start.