again, notably in the Spanish wars, and in the wars of Louis XIV., and
in the wars of the Revolution. To some extent you have seen the same
thing in the present war.

To save Paris was exceedingly important, next came the zone outside
Paris, and so on up to the frontier.

But with the modern German Empire it is exactly the other way, and the
situation is that which we found in Sketch 12; the four external
corners are the essentials which must be preserved from invasion, and
if any one of them goes, the whole political situation is at once in
grave peril.

The strategical position of modern Germany is embarrassed because each
of these four corners must be saved by the armies. 1 is
Belgium--before the war indifferent to Germany, but now destined to be
vital to her position--2 is East Prussia, 3 is Alsace-Lorraine, 4 is
Silesia, and the German commanders, as well as the German Government,
must remain to the last moment--if once they are thrown on the
defensive--in grave indecision as to which of the four can best be
spared when invasion threatens; or else, as is more probable, they
must disperse their forces in the attempt to hold all four at once. It
is a situation which has but rarely occurred before in the history of
war, and which has always proved disastrous.

Germany then must--once she is in Belgium--hold on to Belgium, or she
is in peril; she must hold on to East Prussia, or she is in peril; she
must hold on to Alsace-Lorraine, or she is in peril; and she must hold
on to Silesia, or it is all up with her. If there were some common
strategical factor binding these four areas together, so that the