34 International Relations Theory of War
the war. Germany had to contract territorially at the end of the two world
wars, and Japan was forced to contract territorially at the end of the Sec-
ond World War.
The prevention of territorial expansion of great powers at the end of
central wars stems from the way in which multipolar systems affect the
values of the two transhistorical order principles that constantly act in the
international system. The anarchy principle will spur the two superpowers
to tend always to territorial expansion, owing to their tremendous capabil-
ities, whereas the opposing result—territorial expansion of a great power
at the end of central wars in which it will participate—may lead to the
collapse of the system, a result that the principle of homeostasis dictates to the
players to act to prevent.
The other territorial outcome, territorial expansion, cannot occur at
the end of central wars that are fought in multipolar systems. Territorial
expansion of great powers in multipolar systems at the end of central
wars in which they participate may impair the homeostasis. A rise in
the land power of a great power that acquires a new territory at the
expense of another great power must lead to an increase of its total
power. Following this, the equilibrium will be violated and the homeo-
stasis threatened. This outcome may impair the polarity of the system,
a phenomenon that the homeostasis principle dictates to players to act to
prevent.
Multipolar systems will permit the expansion of great powers at the end
of major or minor wars involving them, inasmuch as the territorial expan-
sion of great powers will not raise the expanding power to potential hege-
mon status in the system and cannot cause the system to collapse—a result
that the homeostasis principle allows to occur.
In the period assessed in the study, 1816–2016, there have been two mul-
tipolar systems, 1849–1870 and 1910–1945, and many major or minor wars
were fought in them. At the end of these wars, the system allowed for the
territorial expansion of the great powers. The multipolar system of the
19th century allowed Prussia to expand territorially in its unification wars,
and the multipolar system of the 20th century allowed Italy to expand in
its war against Ethiopia (1935–1946).
This outcome—territorial expansion of great powers at the end of major
or minor wars in multipolar systems—stems from the manner in which
multipolar systems affect the values of the two transhistorical order prin-
ciples that constantly act in the international system. Thus, while the anar-
chy principle will spur the great powers to tend always to expand through
their tremendous capabilities, this result will not conflict with the other
order principle of homeostasis, inasmuch as a rise in the land power of great
powers at the end of major or minor wars may not cause the system to
collapse—a result that the homeostasis principle does not resist and there-
fore allows to occur.