Thus, in this diagram, the government of the general oblong, A, may distinguish four special zones, the protection of which from invasion is important, but which vary in the degree of their importance.  The least important is the outermost, 1; the more important is an inner one, 2; still more important is 3; and most important of all is the black core of the whole.

Some such arrangement has been the salvation of France time and time 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 defence of one should involve and aid the defence of all, the difficulties thus imposed upon German strategy would be greatly lessened.  Though even then the mere having to defend four outlying corners instead of a centre would produce confusion and embarrassment the moment numerical inferiority had appeared upon the side of the defence.  But, as a fact, there is no such common factor.  Alsace-Lorraine and Belgium, East Prussia and Silesia, stand strategically badly separated one from the other.  Even the two on the East and the two on the West, though apparently forming pairs upon the map, are not dependent on one system of communications, and are cut off from each other by territory difficult or hostile, while between the Eastern and the Western group there is a space of five hundred miles.

Let us, before discussing the political embarrassment to strategy produced by these four widely distant and quite separate areas, translate the diagram in the terms of a sketch map.