Int Rel Theo War

Table 4.7Causes of War by Periods, 1816–2016Type of Polarity

Number of Wars

Frequency of Wars

Average Length of wars

Severity of the Wars

The Six Instances of Polarity,

1816–2016

Central Wars

Major Wars

Minor Wars

Length of the System in Years

War Years

1

% of Years in which a War Was Fought

2

Average Length in Days

Total Killed in Combat Only

Bipolarity,

1816–1848

0

0

1

33

1.4

4%

507

130,000

Multipolarity, 1849–1870

0

5

0

22

3.6

16%

1,312/5=262.5

539,594

Bipolarity, 1871–1909

0

0

0

39

0

0

0

0

Multipolarity, 1910–1945

2

2

9

36

22.5

62%

8,230/13=633

26,639,062

Bipolarity, 1946–1991

0

0

4

46

11.3

25%

4,135/4=1,033

1,975,418

Unipolarity, 1992–2016

(^32)

24

3.1

13%

1,125/2=562.5

39,092

1 The war years were calculated by dividing the total number of days by 365 (the length of one year). The bipolar system 1816–1853: a total of 507

days of war, or 1.4 years of war; the multipolar system of 1854–1870: a total of 1,312 days of war, or 3.6 years of war; the bipolar system of 1871–1909: a total of 0 days of war, or 0 years of war; the multipolar system of 1910–1945: a total of 8,210 days of war, or 22.5 years of war; the bipolar system of 1946–1991: a total of 4,148 days of war, or 11.4 years of war; the unipolar system of 1992–2016: a total of 1,125 days of war, or 3.1 years of war.

2 The percentage of years in which a war was fought was calculated by dividing the years of war by the length of the system in years. The bipolar

system of 1816–1853: 1.4 years of war out of 38 years—4%; the multipolar system of 1854–1870: 3.6 years of war out of 17 years—21%; the bipolar system of 1871–1909: 0 years of war out of 39 years—0%; the multipolar system of 1910–1945: 22.5 years of war out of 36 years—62%; the bipolar system of 1946–1991: 11.4 years of war out of 46 years—25%; the unipolar system of 1992–2016: 3.1 years of war out of 24 years—13%.

3 In unipolar systems, every war involving the polar power, or the sole hyperpower constituting the system, may be included in the three categories

of war: central war, major war, or minor war. Therefore, the three cells relating to the two wars in which the sole hyperpower, the United States, in the unipolar system of 1992–2016, were merged.