Authored by Chris Hamilton via Econimica,
The change in nations Core populations (25-54yr/olds) have driven economic activity for the later half of the 20th century, first upward and now downward.  The Core is the working population, the family forming population, the child bearing population, the first home buying, and the credit happy primary consumer.  Even a small increase (or contraction) in their quantity drives economic activity magnitudes beyond what the numbers would indicate.
To highlight the linkage of Core populations to economic activity, the chart below shows the European 25-54yr/old population vs. the best indicator of economic activity, total energy consumption (data available starting from 1980).  The implications are pretty straightforward.  European economic activity (& resultant energy consumption) will contract for decades, at a minimum, with the declining Core population.  The pie is shrinking and now it’s simply a fight for who gets bigger slices.
Given this, consider Germany was well aware of it’s post WWII collapsing birth rate and the impact of this on economic growth as this shrinking population of young made it’s way into the Core.  Consider Germany’s Core population peaked in 1995 and it’s domestic consumer base has been shrinking since, now down over 3.

Submitted by Chris Hamilton via Econimica blog,
The Maginot Line formed France’s main line of defense on its German facing border from Belgium in the North to Switzerland in the South.  It was constructed during the 1930s, with the trench-based warfare of World War One still firmly in the minds of the French generals.  The Maginot Line was an absolute success…as the Germans never seriously attempted to attack it’s interconnected series of underground fortresses.  But the days of static warfare were over – in 1940, the Germans simply drove around the line through Holland and then Belgium.  Had the Germans replayed WWI and made a direct attack, the Maginot Line likely would have done its job.  But Hitler wasn’t interested in a WWI re-do, so the fortifications were quickly rendered moot.  France, Europe, and the world would pay the price for generals fighting the last war rather than adjusting to the contemporary risks they faced.
In 2008, the economic generals at the various central banks likewise pulled out the playbook to refight the great depression… not realizing, this time was an entirely different opponent.  Federal governments and central bankers presumed doing what they had always done would again win the day.