1. Lecture 4: Sources of International Law: Custom and Treaties
Government 1740
INTERNATIONAL LAW
Summer 2006
Lecture 4: Sources of International Law:
Custom and Treaties

2. OUTLINE I. Sources of International Law
II. Customary International Law (CIL)
What it is
Theories critical of CIL
II. The Nature of Treaty Obligations
A. Definition
B. Pacta Sunt Servanda
C. The Vienna Convention
D. Invalid Treaties
III. How Treaties are Made: From Negotiation to Interpretation
IV. Treaty Termination: cooperatively, unilaterally, and exceptional circumstances

3. I. Sources of International Law
Article 38 of the International Court of Justice:
Treaties
Custom
General Principles of Law
Judicial Decisions
Writings of Jurists
How do we go about determining what rules apply to a dispute? Where do we look for the rules? There is no international constitution; the body of international law is very decentralized.
The classification of various sources is pretty well accepted (created by the International Court of Justice:
[Slomanson talks about whether the order of these matter . Think about which you think are most important and most legitimate.]
[Why even bother with “general principles” etc.? Gap filling function.]
Equity
Judicial independence
The right to examine the evidence against you
Judicial decisions – lots of quotations and review of ICJ decisions. Are these precedents? What is their status? [art 59 – not binding force except between parties]
Roper v. Simmons (2005): juvenile death penalty case (US Supreme Court). Majority decision written by Justice Kennedy refers to a global trend to abolish the juvenile death penalty.
Backlash in the US judiciary and congress against “importing foreign” interpretations when interpreting US constitution. Scalia, Rehnquist, and Thomas.
Scholarly writings – today are references, not sources of obligation. (imagine that backlash!)

4. Customary International Law The “Traditional View”
Rules that evolve from state practice
What constitutes custom?
Broad acceptance, regularity, duration of a practice
Opinio juris
Why is custom is binding?
The contestation of custom – critics?

5. Theories Critical of Customary International Law
Normative critique: weakly linked with consent.
Positive critique:
CIL does not explain foreign policies or world politics.
It only reflects the interests and practices of the most powerful
Normative critique:
Customary international law is only weakly associated with consent.
Consent is the only way that sovereign states can be bound by international rules.
Positive critique (Goldsmith and Posner):
CIL as traditionally defined dos not exist.
Patterns of behavior are at best weak or even irratic.
States rarely can be said to act out of a concern for opinio juris.
They act out of their own self-interest.
interests, not a sense of legal obligation, drive international outcomes.
Coincidence of interests:
Maybe US and Canada – find each other in their respective exclusive economic (fisheries) zones. Laws or no laws, and no matter what the other country does, it does not make sense to attack. Law does not matter.
Interest in coordination:
Why do 150 students, 2 TFs, and 1 professor come here at 10:00 am? There is no law. It would make no difference if there were. And the fact that you keep coming at that time does not in any way change your OBLIGATION to come.
environment
interests
behavior

6. Other sources of International Law
General Principles of law
Judicial Decisions
Writings of Jurists

7. II. The Nature of Treaty Obligations
An international agreement between two or more subjects of international law which is intended to create rights and obligations for the parties to it
Treaty = covenant = pact = agreement=accord (see Slomanson on the many synonyms)
An international agreement between two or more subjects of international law which is intended to create rights and obligations for the parties to it.
usually between states, though can be concluded by IOs as well.
(example: agreements to establish IOs on national territory.)
sometimes states/provinces in a federation
sometimes the Roman Catholic Church (historical reasons)
- [An agreement between a company and a government is not a treaty]
Treaties dominate International Law.
US a party to thousands of bilateral Treaties.
US a party to over 600 multilateral conventions.
Treaties exist alongside customary int'l law, but where there is a conflict:
treaties tend to take precedence
because of the strong principle that sovereign states must consent to international obligations.
(This is why the newer and communist states and revolutionary states have preferred treaties to customary international law).
Treaties are the main source of international obligations.
38 of the statutes of the International Court of Justice:
It instructs the ICJ judges to apply "international conventions whether general or particular, establishing rules expressly recognized by the contesting parties."
Thus a treaty is law for those parties which have signed it.

8. Basic Principles of Treaty Law
Pacta Sunt Servanda: Agreements must be served; they are binding
1969 Vienna Convention on the Law of Treaties
Analogy: treaties and contracts. Consent based obligations, with protections for contracting parties.
PACTA SUNT SERVANDA - agreements must be served; they are binding.
[but note that "revolutionary" states have argued that they should not be bound by "unequal treaties" which were made when they were in a position of weakness.
E.g., China in the twentieth century has disavowed nineteenth century treaties with the Tsarist Empire in which the latter annexed its territory.]
Revolutionary Iran disavowed some treaties made under the Shah. Argued that international law could not bind a nation based on Islam.
Cuba has disavowed the Guantanamo base agreement with the US, though they are not in a position to do anything about it.
THE CENTRAL INSTRUMENT DEFINING TREATY LAW:
The 1969 Vienna Convention on the Law of Treaties:
-This is the Treaty on how to make treaties!
- The US is not a party to this Treaty, but recognizes it as a codification of customary international law.
This agreement is the basis for much of the rest of this lecture.
Note also: it is a good example of secondary rules in HLA Hart’s sense: Rules about how substantive rules are to be made.

9. Invalid Treaties Unauthorized negotiator Essential error of fact
Impose obligations on third parties
When are treaties invalid?
1. if the other party was informed that the negotiator did not have full powers. (invalidates the agreement). [concern: when there are internal power struggles]
2. If a party was in error with regard to a fact or condition which was an essential basis of its consent.
(But not if it contributed to the error or was forewarned of the possibility of error.)
[principle: consent should be “fully informed”]
3. Invalid when its purpose is to impose an obligation on a third party.
[one exception: bilateral territorial agreements between states should be recognized as binding on other states.]

10. Invalid Treaties Against prevailing norms or illegal
.If the purpose of the Treaty is against prevailing norms or is illegal.
(e.g., a pact of aggression against another state; and agreement to divide up and occupy another state, like Stalin and Hitler did with Poland.)
if the treaty contradicts “jus cogens” – a “preemptory norm of international law” that prohibits certain acts even if states explicitly consent to them.
[domestic analogy: contracts to perform murder are illegal]

11. Concluded under the threat or use of force (VCLT Article 52)
Invalid Treaties?
Concluded under the threat or use of force (VCLT Article 52)
Treaty of Nanking
If the treaty was achieved under the threat or use of force.
[principle: coerced contracts are not enforceable]
[Some states have argued that "force" should be interpreted broadly to include economic, social, or political coercion.
But you could argue that all treaties have something to do with pressure or counter pressure. That's what international politics is all about.]
[China refused to recognize "unequal" treaties.
But how do you define unequal? Can it be inferred from a power disparity between states? That would make it impossible for the United States to conclude a treaty with Panama.
The Chinese emphasize that a treaty must provide mutual benefit - otherwise there would have been no reason to conclude it.
They even use the phrase, "identical and reciprocal" obligations. But a state may be willing to bind itself asymmetrically if the goal of the agreement is important enough to it.]
Opium Wars

12. Invalid Treaties? Concluded under the threat or use of force
Treaty of Versailles
Concluded under the threat or use of force
What about agreements made upon surrender? (peace treaties?)
should they be invalid?
Germany thought so, regarding the Versailles Treaty
Germany to: - Reduce army to 100, Reduce the navy to 6 warships; no submarines. - Destroy all of its air force. - Give land to Belgium, France, Denmark and Poland.
Hand over all of its colonies. - Agree to pay Reparations of £6,600,000, Accept demilitarized Rhine. - Accept the "War Guilt Clause".
But the terms of surrender do usually represent “victor’s justice”
While the Versailles Treaty was viewed as a political mistake, it was not widely viewed as invalid.

13. Invalid Treaties? Concluded under the threat or use of force
If the treaty was achieved under the threat or use of force.
Article 52 of the Vienna Convention
[principle: coerced contracts are not enforceable]
The base was established in 1898 when the U.S. obtained control of Cuba from Spain at the end of the Spanish-American War.
The U.S. government obtained a permanent lease for the base on February 23, 1903 from the newly independent Cuban state. ($2,000/year).
The Cuban government never cashes the treasury check because it views the base as illegitimate.
As of 2004, it is still occupied by the US.
The Cuban Government strongly denounces the treaty on grounds that the Vienna Convention on the Law of Treaties, Article 52 that a treaty is void if its conclusion has been procured by the threat or use of force.
Cuba complained that US troops would not leave its soil in 1903 without the base agreement as is. (They’ve cut off water, forcing US to import water from Jamaica, etc.)
Guantanamo Bay

14. III. How Treaties are Made
Negotiation
All treaties begin with politics
Shaped by power, interests, bargaining, and persuasion.
.Negotiation stage.
Treaties begin with politics. There are diplomatic conventions about how these things take place, but ultimately negotiations are shaped by power relations, interests, and persuasion.
May involve heads of state or experts.
May be series of conferences. (UNCLOS - nearly a decade.)
[International Organizations may have mechanisms for writing a convention and may submit it for the membership to vote on.]
credentials of negotiators are important (if they are lacking this could invalidate the treaty)
The object at this stage is to come up with a text.

15. Treatymaking, continued...
Adoption: agreement on a final text
Signature: signing of adopted text
B. Adoption. – Agreement on the final text.
In a bilateral text, agreement through consensus.
Multilateral: may need a vote.
[NB: A country can vote against the text, like the US did against the Law of the Sea text in The US had been involved from the beginning of the negotiations, but the Reagan administration decided to opt out.]
.Signature.
Treaties are formally "adopted" when they are signed.
this does not formally bind a state
allows it to participate in further multilateral discussions
E.g., the US has signed the Rome Treaty creating the International Criminal Court. Purpose: to participate, but not to become obligated.
Ratification:
Treaties do not bind until they are ratified.
Ratification is done by the executive of each country, according to domestic rules
usually the legislature has to ratify a treaty.
In the US, 2/3 vote of the Senate is required. But the President actually ratifies "with the advice and consent of the Senate."
- Ratification is only binding after both countries have signed.
Ratification: done by the executive
of each country, according to
domestic rules that typically involve the legislature

16. Reservations:
“...the exclusion or modification of the legal effect of certain treaty provisions.”
Reservations almost never occurs in bilateral treaties; might as well renegotiate.
Extremely complicating in the case of multilateral treaties, because some parties may accept the reservations and some may not. What if some of the signatories reject the reservation? does it make the treaty invalid for all? for some of the parties?
What does the Vienna Convention Say?
Article 20: when the “object and purpose” of the treaty seems to require that all states sign on to the agreement in its entirety, reservations require acceptance by all parties.
[For more on the admissibility of reservations, see Articles of the 1969 Vienna Convention.

17. ICCPR Reservations: United States:
"(2) That the United States reserves the right, subject to its Constitutional constraints, to impose capital punishment on any person (other than a pregnant woman) duly convicted under existing or future laws permitting the imposition of capital punishment, including such punishment for crimes committed by persons below eighteen years of age.”

18. Other Aspects of Treaty-making
Accession/Adhesion
Entry Into Force
Interpretation
F. Accession/Adhesion
a country which was not involved in the negotiation may want to agree to adhere to the agreement.
[But there are some international agreements to which it is difficult to become a formal adherent. E.g., the European Community. Turkey has asked to be a member of the EC and they won't let them in.]
[The US has said publicly that it will adhere to the Vienna Convention even though it has not ratified it.]
G. Entry Into Force:
- after all requirements of international law are met.
typically done by domestic legislation which brings the treaty into force.
E.g, the Vienna Convention came into force when the 35th state ratified it in Jan.’80
Treaties are deposited with the United Nations. (Meant to prevent secret agreements such as that between Stalin and Hitler regarding the partition of Poland in 1939.)
H. Interpretation: [next time: discuss ABM Treaty]
What happens if parties to the Treaty interpret its meaning differently?
See articles of the 1969 Vienna Convention.
Parties should try to reach an "agreed authentic interpretation" between themselves.
Parties may submit the treaty to interpretation by an int’l tribunal or the ICJ.
What should be taken into consideration in interpreting the treaty?
ordinary meaning of the words used in the treaty.
intentions of the parties that negotiated the treaty.
the object and purpose of the treaty.
General Rule: When in doubt, the interpretation which involves the minimum obligation for the parties should be chosen.

19. IV. Treaty Termination Terms of the Treaty itself Notice
Explicit or Tacit Agreement
Violation by one side
Clausula rebus sic stantibus
State Extinction
Treaties do not last forever. Necessary to find some way to terminate them; conditions change. Termination can take place through:
A. Terms of the Treaty itself. May provide that it applies only for a certain number of years.
E.g., the Warsaw Pact was supposed to last for 20 years ( ).
But the Pact provided for extension for 10 more years, after which it would have to be renegotiated, which occurred in 1985.
But it was abrogated in February 1991.
B. Notice. Each side can give notice that they no longer intend to be bound by the treaty. Usually, there is a stipulated period between giving notice and actual termination, e.g., 6 months.
-E.g., The Carter Administration gave notice to Taiwan in 1979 that the Mutual Defense Agreement with Taiwan would be abrogated.
-E.g., When it was clear that East and West Germany would unite, E. Germany began to give notice that it would no longer consider itself bound by its external obligations.
C. Explicit or Tacit Agreement.
Explicit abrogation is what happened to the Warsaw Pact.
A tacit agreement: where a new treaty is negotiated which supercedes the old one.
D. Violation by one side.
This is often claimed as a legitimate pretext for the other side to withdraw.
E.g., Sadam's 1980 abrogation of the border agreement on the Shatt-al Arab with Iran. Claimed Iran had been the first to violate the agreement.
E. Clausula rebus sic stantibus.
A Party to the Treaty may void it by claiming a fundamental change in circumstances.
1969 Vienna Convention, article 62:
"A fundamental change of circumstances which has occurred with regard to those existing at the time of the conclusion of the Treaty, and which was not foreseen by the parties."
Not frequently claimed, but it is an important escape clause for states.

20. Summary:
Treaties are the most important source of international law, followed by custom
Custom requires a pattern of behavior, as well as a widespread belief that a norm is obligatory (opinio juris)
Pacta sunt Servanda: Treaties are to be observed
Secondary rules have developed on Treaty Law: Vienna Convention 1969
Through Treaty Law, states are trying to achieve a balance between:
Certainty and Flexibility
Obligation and Consent