"In the second half of the 20th century, the United States enjoyed stature and prosperity at levels seldom achieved in recorded history. The country's status included predominance in most fields of science and technology (S&T), as well as a phenomenal breadth and pace of innovation. We are now experiencing a global shift to a more level playing field among nations; demographics, economics, and political forces are the driving forces behind this shift. The impact of this shift on U.S. S&T will be significant. By the middle of the 21st century, it is likely that a number of nations will be similarly prosperous and technologically productive. No single nation or group will dominate as the United States did in the latter half of the 1900s. The U.S. share of the global S&T enterprise will decrease, and only a small fraction of U.S. scientists and engineers (S&E) will work on national security problems. This change poses challenges to the roles and conduct of Department of Defense (DOD) S&T. In particular, DOD's ability to maintain an authoritative awareness of S&T developments around the world will become increasingly problematic."
National Defense University: http://www.ndu.edu/