Peoples living
under modern conditions and by use of the modern state of the industrial
arts necessarily draw on all quarters of the habitable globe for
materials and products which they can procure to the best advantage
from outside their own special field so long as they are allowed access
to these outlying sources of supply; and any arbitrary limitation on
this freedom of traffic makes the conditions of life that much harder,
and lowers the aggregate efficiency of the community by that much.
National self-sufficiency is to be achieved only by a degree of economic
isolation; and such a policy of economic isolation involves a degree of
impoverishment and lowered efficiency, but it will also leave the nation
readier for warlike enterprise on such a scale as its reduced efficiency
will compass.

So that the best that can be accomplished along this line by the
dynastic statesmen is a shrewd compromise, embodying such a degree of
isolation and inhibition as will leave the country passably
self-sufficient in case of need, without lowering the national
efficiency to such a point as to cripple its productive forces beyond
what will be offset by the greater warlike readiness that is so
attained. The point to which such a policy of isolation and sufficiency
will necessarily be directed is that measure of inhibition that will
yield the most facile and effective ways and means of warlike
enterprise, the largest product of warlike effectiveness to be had on
multiplying the nation's net efficiency into its readiness to take the
field.

Into any consideration of this tactical problem a certain subsidiary
factor enters, in that the patriotic temper of the nation is always more
or less affected by such an economic policy. The greater the degree of
effectual isolation and discrimination embodied in the national policy,
the greater will commonly be its effect on popular sentiment in the way
of national animosity and spiritual self-sufficiency; which may be an
asset of great value for the purposes of warlike enterprise.

Plainly, any dynastic statesman who should undertake to further the
common welfare regardless of its serviceability for warlike enterprise
would be defeating his own purpose. He would, in effect, go near to
living up to his habitual professions touching international peace,
instead of professing to live up to them, as the exigencies of his
national enterprise now conventionally require him to do. In effect, he
would