or in the concept of the nation-in-

or in the concept of the nation-in-arms and the impact
of the Industrial Revolution. The nation-inarms
provided huge armies, while the Industrial
Revolution provided the means to equip,
deploy, command, and sustain them. The
result was that whereas in the wars of the 18th
century, armies in the field seldom exceeded
150,000, Napoleon invaded Russia in 1812
with 600,000 men, and the Prussians invaded
France in 1870 with 1,200,000. As a result of
this increase, the size of the battlefield grew
from a few kilometers wide in Frederick the
Great’s time to several hundred kilometers in
France in 1871