98 International Relations Theory of War
between powers may break out: a war between the two competing polar
powers. The great powers that are not polar powers in the system are not
in a position that allows them to defeat one of the two superpowers. Bipo-
lar systems are rigid. The two polar powers will force the other great pow-
ers that are not polar powers to join forces with one of them, and almost no
powers that are not aligned with one of the major blocks will remain. The
transition from one side to the other is rare too. In addition, great powers
have few possibilities of turning the polar powers against each other. This
fact leads to the relatively great stability of these systems compared with
the other polarity models.^92
The current study bases its conclusions on three bipolar systems, 1816–
1848, 1871–1909, and 1946–1991. The definition of the first two periods as
bipolar contrasts this study with most theoretical studies in international
relations regarding two main subjects. Firstly, the first two periods are
assigned by most international relations theorists to the multipolar model
that in their opinion prevailed from the time of the modern states system’s
formation in 1648 to the end of the Second World War in 1945. The other,
the relative stability of these two periods, is attributed by many studies to
the European Concert, while the current study attributes it to bipolarity.
The first debate was discussed in chapter 3 (the independent variable,
the polarity of the system), in which the discussion of the various polar-
ity models and the definition of these two outcomes as bipolar were pre-
sented. Following is the second debate, in which I rule out the alternative
explanation in international relations research for the stability of these two
periods.
The Stability of the Bipolar System, 1816–1848, 1871–1909The two long periods of peace in 1816–1848 and 1871–1909 are attributed
in the current study to the bipolarity that existed in the system. In theo-
retical international relations research, in contrast, a number of alternative
explanations to this relative calm are commonly accepted. One explanation
indicates the equal division of power between the great powers in Europe
as a factor for peace and stability. Mearsheimer argues that throughout
most of the 19th century until the 1920s, in 1815–1853 and 1891–1914, there
was an equal distribution of powers between the European great powers
and it was responsible for the peace and stability of the continent. In these
two periods, there was no country with hegemonic aspirations in Europe.
France, the strongest country in the early 19th century, lost its greatness
to assume a position on par with its key rivals, whereas Germany started
to appear as a potential hegemon only in the early 20th century.^93 Accord-
ing to the other explanation, the long difficult wars against revolution-
ary France in 1787–1815 formed an aspiration for peace and diplomatic
arrangements, such as the European Concert, and European leaders’