The great difficulty in forecasting the future strategic environment and the force structure needed in response is the plethora of variables that change the calculus. Only hindsight reveals the failure of a Maginot Line or the brilliant success of a mechanized Blitzkrieg doctrine. In the final analysis, the reader must judge the line of reasoning. In this monograph, Dr. Steven Metz and Lieutenant Colonel Raymond Millen examine the trends in the strategic environment in their development of the Future War/Future Battlespace. One fact is clear. Traditional warfighting has changed in the post 9-11 era. The U.S. military must adapt or fail. There is no other recourse. Dr. Metz and LTC Millen have superbly framed the strategic environment into four strategic battlespaces and have examined the ways future adversaries will operate within them to thwart U.S. strategic initiatives.