done, and each side is made by its government to think itself very
virtuous and wholly justified in its killing. It should be the great
aim of everyone today to help to bring about lasting peace among all
the nations.

[Illustration: A Drill Ground in Modern Europe.]

In order to know how to do this, we must study the causes of the wars
of the past. We shall find, as we do so, that almost all wars can be
traced to one of four causes: (1) the instinct among barbarous tribes
to fight with and plunder their neighbors; (2) the ambition of kings
to enlarge their kingdoms; (3) the desire of the traders of one nation
to increase their commerce at the expense of some other nation; (4) a
people's wish to be free from the control of some other country and to
become a nation by itself. Of the four reasons, only the last
furnishes a just cause for war, and this cause has been brought about
only when kings have sent their armies out, and forced into their
kingdoms other peoples who wished to govern themselves.


Questions for Review

1. Why must foreigners in the United States return to their native
lands when summoned by their governments?
2. How is it that war helps to breed diseases?
3. Is race hatred a cause of war or a result of it?
4. Whom do we mean by the government in the United States?
5. Who controls the government in Russia?
6. Who in England?
7. Who in Germany?