second point of difference between the expansion of peoples and of
states lies in their respective relation to the political frontier. This
confines the state like a stockade, fixing the territorial limits of its
administrative functions; but for the subjects of the state it is an
imaginary line, powerless to check the range of their activities, except
when a military or tariff war is going on. The state boundary, if it
coincides with a strong natural barrier, may for decades or even
centuries succeed in confining a growing people, if these, by
intelligent economy, increase the productivity of the soil whose area
they are unable to extend. Yet the time comes even for these when they
must break through the barriers and secure more land, either by foreign
conquest or colonization. The classic example of the confinement of a
people within its political boundaries is the long isolation of Japan
from 1624 to 1854. The pent-up forces there accumulated, in a population
which had doubled itself in the interval and which by hard schooling was
made receptive to every improved economic method, manifest themselves in
the insistent demand for more land which has permeated all the recent
policy of Japan. But the history of Japan is exceptional. The rule is
that the growing people slowly but continually overflow their political
boundary, which then advances to cover the successive flood plains of
the national inundation, or yet farther to anticipate the next rise.
This has been the history of Germany in its progress eastward across the
Elbe, the Oder, the Vistula and the Niemen. The dream of a greater
empire embraces all the German-speaking people from Switzerland, Tyrol
and Steiermark to those outlying groups in the Baltic provinces of
Russia and the related offshoot in Holland.[314] [See map page 223.]

Though political boundaries, especially where they coincide with natural
barriers, may restrict the territorial growth of a people, on the other
hand, political expansion is always a stimulus to racial expansion,
because it opens up more land and makes the conditions of life easier
for an increasing people, by relieving congestion in the older areas.
More than this, it materially aids while guiding and focusing the
out-going streams of population. Thus it keeps them concentrated for the
reinforcement of the nation in the form of colonies, and tends to reduce
the political evil of indiscriminate emigration, by which the streams
are dis