International Law
Unit 9: Use of Force
Fall 2005
Mr. Morrison
Historical development of use
of force law
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19th Century—War is a legitimate status
20th Century
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Fall 2005
League of Nations Covenant established a
“cooling off period”
Kellogg-Briand Pact (Pact of Paris)
renounced war as instrument of national
policy
But—World War II.
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United Nations Law on Use of
Force
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General denunciation of war
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In preamble
In Purposes: Art. 1(1)
In Principles: Art. 2(4)
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Fall 2005
“All Members shall refrain in their international
relations from the threat or use of force against
the territorial integrity or political independence
of any state, or in any other manner
inconsistent with the Purposes of the U.N.”
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Three Charter Chapters
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Chapter VI—Pacific Settlement of
Disputes (arts. 33-38)
Chapter VII—Action with Respect to
Threats to the Peace, Breaches of the
Peace and Acts of Aggression (arts. 3951)
Chapter VIII—Regional Arrangements
(arts. 53-54)
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Chapter VI—Pacific Settlement
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Security Council can call upon States to
engage in pacific settlement
While Security Council is considering,
General Assembly cannot act (art. 12)
Affected State cannot vote (art. 27(3))
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Chapter VII—Action
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Collective Security (arts. 39-50)
Self-defense (art. 51)
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Collective Security
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Security Council must find “treat to the
peace, breach of the peace, or act of
aggression” (art. 39)
It may call for provisional measures
(art. 40)
It may impose sanctions (art. 41)
It may use force (art. 42)
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Collective Security Issues
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Breadth of “threat to the peace”
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Definition of “acts of aggression”
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Indirect or “reverse” threats
UN Definition of Aggression
Nature of force
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Fall 2005
Original idea: A true joint force
Actual: Frequently authorization for action
by group of States
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Self Defense
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“Nothing in the present Charter shall
impair the inherent right of individual or
collective self-defense if an armed
attach occurs against a Member of the
United Nations, until the Security
Council has taken the measures
necessary to restore international peace
and security . . .” (art. 51)
Fall 2005
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Self Defense issues
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Inherent right
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Individual or collective
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What does the word “inherent” add?
Nicaragua judgment says there must be a
request
Until the Security Council [acts]
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Fall 2005
What extinguishes the inherent right?
Action or complete action?
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Self defense issues
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What is an “armed attack”?
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Objective or subjective test
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Fall 2005
Soldiers crossing border or perceived imminent
threat?
Preemptive and preventive self-defense
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Definition of Aggression
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Adopted by General Assembly Res.
3314 (XXIX)(1974)
Contains both objective and subjective
tests
Intended as interpretation of art. 39,
but may apply to art. 51
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Chapter VIII—Regional
Arrangements
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Regional arrangements may take
“enforcement actions” with the permission of
the Security Council (art. 53)
Note the difference
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Regional arrangement (art. 53)
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Collective self-defense (e.g., NATO) (art. 51)
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Fall 2005
Security council approval required
Security Council approval NOT required
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Humanitarian intervention
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Collective security responses
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UN intervenes (or authorizes intervention)
if there is a “threat to the peace” (art. 39)
and thus domestic jurisdiction rule is
overridden (art. 2(7))
Foreign State intervention (see art. 2(4))
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Fall 2005
To protect its nationals
To stop genocide (Genocide Convention)
Other human rights violations???
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