Why Nations
Go to War

Starter Questions
• Are people naturally peaceful or naturally
violent?
• Who are you more likely to argue with,
your neighbor or someone in Beijing?
• Why do some countries seem to go to war
with each other all the time?
• What happens when one generation in a
country has many more children than the
last?
• Do more weapons lead to less war?

Introduction
• Today we will look at several theories
to explain why nations go to war
• The main focus is interstate war –
war between countries
– We will briefly touch on civil wars
• Many of these theories overlap, and
together they help to form a complete
picture of why war happens

Key Words
• State – another word for a nation
• Regime – the government of a state
• Power – an important state in the
world
– Minor Power – less important states
– Great Power – very important states
– Superpower – the most important states
• System – the character of relations
between states

Key Words
• Treaty – an agreement between states
– Non-Aggression Pact – an agreement not
to attack one another
– Mutual Defense Pact – an agreement to
help out another state if it is attacked
– Alliance – a strong treaty to connect
security and economic interests of states
– Collective Security Pact – an agreement
that a large group of states will work to
maintain peace (for example, the UN)

Looking at Theories
• Now we will learn about ten popular
theories in International Relations to
explain the causes of war
• We will briefly look at each theory and
discuss historical examples for each
• As you may have noticed, important
words will be highlighted in red
• If you have questions, please ask as
we go through the lecture

I. Borders and War

Details of Theory
• It’s common sense that countries go to
war more with their neighbors
• Studies find that Great Powers are
about ten times more likely to fight a
war with their neighbors than to fight
non-contiguous states
• The more borders a state has, the
greater the chance for war or for war
to spread between its neighbors

Other Findings
• Borders only provide opportunity for
war, not incentive
• Natural borders are generally more
peaceful than artificial ones
– What is a “natural” border?
• Mountains
• Lakes
• Seas
– Why is this true?

Example
• The civil war in Congo became Africa’s
first “World War”
– Lasted from 1998 until 2003
– Killed up to 5.4 million people
– Eight different states were involved
• The war spread easily because the DR
Congo borders nine different countries
• Many countries invaded to steal the
Congo’s resources

II. Resource Wars

Details of Theory
• What are some important resources?
• What happens when a country doesn’t
have the resources it needs?
• According to Lenin, capitalist states
engage in imperialism to gain
resources and avoid revolution at
home
• Resource wars are even more common
when resources are in border regions

Example
• The Ruhr, Saar, and Lorraine regions
divide France and Germany and are
rich in coal and iron
• France and Germany have fought over
control of these regions several times
• The European Union began as a treaty
to share resources from the regions
peacefully and avoid future war

III. The Youth Bulge

Details of Theory
• We say a state has
a “youth bulge”
when its population
has an unusually
high number of
young people
• A youth bulge can
lead to social
problems, especially
if the young people
are mostly men

Youth Bulge Problems and
Solutions
• Problems • Solutions
– Lower quality – Improved social
education policies (preferred
– More in the West, but
unemployment expensive!)
– More crime – Revolution by the
(because less jobs) youth
– More unrest – Civil war
– Possibility of – Genocide (killing of
terrorism (many minority social
terrorists are groups)
“angry young men”) – Interstate war

Examples
• Germany during the 1930s had a youth
bulge that Hitler used to his benefit
• So did Japan during World War II
• China during the 1960s experienced a
large youth bulge that contributed to the
Cultural Revolution
• Islamic terrorism takes advantage of the
youth bulge in Muslim countries today

IV. A Power Imbalance

Details of Theory
• The international system is made up
of many powers great and small
• These powers tend to “balance” each
other by forming alliances
• Because of balancing, war is avoided
because no powers have an advantage
• Sometimes, however, new technology
or internal problems in a powerful
state can disrupt the balance of power

Examples
• The Sino-Japanese Wars of 1894-95
and 1931-45 happened because the
balance of power between China and
Japan was lost – why?
– Japan adopted Western technology and
methods; China rejected them
– Chinese government was unstable
because of the Qing collapse and later the
civil war
– The loss of Chinese power relative to
Japan created an opportunity for war

V. Flaws in the System

Details of Theory
• The international system is supposed to
balance powers, but it requires freedom
– States must be able to enter and leave
treaties freely
– States should freely choose wars rather than
be forced into wars by alliance partners
• Flaws in international treaties, combined
with mistakes in diplomacy may increase
rather than decrease war

Examples
• World War I began because of
interlocking treaties between powers
in Europe
– It was against the interest of the states
to engage in war, but they were
compelled by treaties to fight each other
• The Opium Wars between China and
France and Britain happened in part
because of profound differences in
diplomacy and expectations

VI. Leadership Miscalculation

Details of Theory
• What does “it takes two to tango”
mean?
• Leaders choose war when they have
an advantage, avoid war when weak
– If a weak power is threatened by a strong
power they may offer concessions
– If a leader mistakenly thinks he/she has
an advantage, he/she may enter a war
that should be avoided

Examples
• During the Boxer Rebellion, Cixi fought
the Eight Powers because she believed
that she had the power to defeat them
• The US fought the war in Vietnam
because it thought that it could outlast
the communists
• Saddam fought the coalition in the first
Gulf War because he didn’t think they’d
actually attack him – he was playing a
“game of chicken”

VII. Para Bellum

Details of Theory
• Si vis pacem praeparat para bellum – if
you desire peace, prepare for war
• States may go to war because they see
their opponents as weak
– Their opponents lack the necessary
deterrence to prevent war
• During a civil war, deterrence is lower
and the chance of being invaded by
another state is greater

Policy Applications
• America, Russia, China, and other great
powers tend to believe in this theory
• Many Americans argue that
disarmament after World War I
encouraged Hitler
• Nuclear deterrence is the best example of
applied “para bellum” theory – for 60
years there have been no other systemic
wars because of nuclear weapons

VIII. Diversionary War

Details of Theory
• How can leaders distract from bad
news at home?
• Answer: Fight a war abroad!
• During the war or military action,
public attention will shift away from
domestic troubles – we call this a
diversionary war
• Democratic leaders are more likely to
start these kinds of wars

Examples
• If successful, diversionary wars may
boost a leader’s fortunes, such as
Thatcher after the Falklands War
• If unsuccessful, it can mean the end
of a regime, such as the Argentine
junta after the Falklands War
• It can distract the press away from
scandal, such as Clinton’s bombing of
Sudan during the Monica Lewinsky
affair

IX. Ideological or Cultural War

Details of Theory
• States may see other powers with
strong cultural or ideological
differences as a threat against their
interests or way of life
• Often, these states won’t fight each
other directly but engage in proxy
wars
– Germany vs. USSR in Spain
– US vs. USSR in Vietnam
– US vs. USSR in Afghanistan

Other Findings
• Religions often have many wars along
their “borders,” especially Islam in
Africa
• Shared religious identity can create a
zone of peace (e.g. Dar al Islam in
Islam)
• Shared democracy can also create
more peaceful relations
– Kant argued that democracies will turn to
law rather than war to settle disputes

X. Rivalry

Details of Theory
• What are rivals?
• Characteristics of rivalry
– Often, shared borders – but not always
– Different cultural or ideological
backgrounds
– Important history of conflict
• Rivalry is responsible for many of the
wars within the international system
and can cause the most deadly of
wars

Historical Rivalries
• France vs. Germany
• Russia vs. Western powers
• China vs. Japan
• China vs. Russia
• India vs. Pakistan
• Iran vs. Arab states
• Israel vs. Muslim states
• Anglophone vs. Francophone Africa

Reducing Rivalry
• Several changes can reduce rivalry
between countries
– Cultural change – one state becomes
more like the other
– Outside powers – the two states may
share a friend, especially a superpower,
who influences them towards peace
– Alliances and economic relations (e.g. EU
brought about an end to Franco-German
rivalry)

The End
Any questions?