Military Use of Underground Terrain

The use of man-made underground environments for military operations is reported back to about 5500 BP, although the use of natural caves for defensive purposes must date back much further. Regardless of precisely when mankind first used underground terrain for military purposes, this use has continued, and has had a remarkably successful and noteworthy history. It is the contention of this author that military use of naturally occurring or manmade space underground has been underrated in its contribution to sustained military operations. Retaliatory strikes in Afghanistan subsequent to the September 11, 2001 terrorist attacks against the US have demonstrated the strategic as well as the tactical importance of underground terrain, and as such, have shown that its military use is now more important than it has ever been on a global scale, and may soon challenge outer space as the pivotal battlefield of the future.