dependent upon the swift overthrow of France; and this in turn hinged
upon the question as to whether German armies could invade France before
the French were ready. Speed was the essential thing, and in order to
gain speed Germany committed one of the greatest crimes in modern
history.

From the nearest point on the German boundary to Paris is only one
hundred and seventy miles. But no rapid invasion of France could be made
in this direction for two reasons: first, because of the very strong
forts which protected the French frontier; and second, on account of the
nature of the land, which presents to the east a series of five easily
defended ridges, each of which would have to be stormed by an invader. A
German attack directly across the French frontier could move but slowly
past these natural and military obstacles; and the French nation would
have ample time to mobilize its forces.

Consequently the German military leaders determined to attack France
from the northeast. Here a comparatively level plain stretched from
Germany through Belgium and France up to Paris itself. Many good roads
and railways traversed the land. Few natural barriers existed to aid the
defenders, and France, trusting to the neutrality of Belgium, had no
strong fortifications on her northeastern frontier. One obstacle to
German invasion existed; it was what the German Chancellor once[2]
called "a scrap of paper"--a promise to respect the neutrality of
Belgium, which Prussia, France, and England had agreed to by formal
treaties. Similar treaties guaranteed the neutrality of Luxemburg, a
small country east of Belgium. Upon these promises France had depended
for the protection of her northeastern border; for the German Empire had
accepted all the rights and all the duties of the treaties made by
Prussia. But now, under the plea of necessity which "knows no law," the