Military analysts are always talking about strategy. Often they are proposing one that they have just invented and naturally think will be the solution to the nation's security problems. The present time, filled as it is with the threat of Islamist terrorism and with the debacle of the Iraq War, is especially marked by the proliferation of strategic proposals.

More seasoned analysts know, however, that if any strategy is to prove effective, it must fit social and structural realities, including the state of technology, the economy, and the political system. Less noted is the role of demography.

Until recently, demographic changes were so slow that they hardly seemed to be a variable effecting strategic challenges. But today, many major nations are undergoing rapid and evident changes in their demographic structure. This is most obvious in Europe, but it is also the case in the United States, Russia, China, and Japan. Demographic disruption is impacting America, all of its major allies, and all of its traditional or potential adversaries. [...]