# The International Legal Order

Law I · Foundations of Law · https://tryals.app/learn/law-i/the-international-legal-order

## Law Without a Legislator

International law is made by the entities it binds. There is no global parliament or police force. It is **decentralised** law, created and enforced by states themselves.

### The Sources

Article 38 of the Statute of the International Court of Justice lists **Three** primary sources:

- **International conventions**: formal treaties between states.
- **International custom**: practice accepted as law.
- **General principles of law**: fundamental rules recognised by nations.

Judicial decisions and doctrine serve only as **subsidiary means** for finding rules.

**Custom** requires two distinct elements:
- A **general practice** across states.
- **opinio juris**, the conviction that the practice is legally binding.

A **persistent objector** openly opposes a custom from the outset and avoids being bound by it.

**Treaties** are governed by the Vienna Convention on the Law of Treaties. They rely on two fundamental rules:
- **pacta sunt servanda**: treaties bind their parties and require good faith performance.
- **ius cogens**: peremptory norms that void any conflicting treaty.

### Reception in Spanish Law

| | Monism | Dualism |
|---|---|---|
| Legal orders | One | Two, separate |
| Internal effect | Direct | Requires reception |
| Key figure | Kelsen | Triepel |

Under **Article 96.1 CE**, valid treaties enter the Spanish legal order **once officially published in Spain**. Publication grants internal domestic effect, but international validity binds Spain immediately.

### Soft Law

International trade uses standard contracts, arbitration rules, and private codes. Lawyers call these instruments **soft law**. They shape commercial behaviour without formal state enforcement.

> **Common pitfall:** concluding that international law is not law because it lacks a central police force. The system enforces itself through countermeasures, reciprocity, and international institutions. Most states comply because they created the rules themselves.

## Practice questions

8 of this lesson's 13 practice questions, with answers. The full set is in the app.

### 1. Sort each item by the kind of international source it belongs to.

**Answer:**

- Treaty law: Vienna Law of Treaties, United Nations Charter
- Customary law: Head of state immunity, Territorial sea sovereignty
- General principle of law: No profit from own wrong, Right to be heard

**Why:** The third column is the one students leave empty. General principles are rules so widely shared across national legal systems that international tribunals treat them as available, good faith, res judicata, the prohibition on profiting from one's own wrong. They exist to stop a tribunal being paralysed when neither a treaty nor a custom covers the point.

Page: https://tryals.app/practice/law-i/the-international-legal-order/sort-each-item-by-the-kind-of-international-source-it-belongs-to

### 2. Under Article 96.1 of the Spanish Constitution, a validly concluded treaty forms part of the internal legal order once it has been officially published in Spain.

**Answer:** True

**Why:** **True**, and the condition is worth separating from international validity. Spain is bound as a state from the moment the treaty is in force for Spain; it becomes part of the *internal* order, applicable by Spanish courts to individuals, on official publication. A treaty can therefore bind the state internationally and not yet be law inside it.

Page: https://tryals.app/practice/law-i/the-international-legal-order/under-article-96-1-of-the-spanish-constitution-a-validly-concluded

### 3. Why can a rule of customary international law bind a state that has never signed anything?

A. A rule binds a state only once that state has ratified an instrument containing it
B. Custom is formed by a general practice of states accepted as law, not by signature
C. Consent in international law may be tacit, expressed through conduct over time
D. A state that objects consistently and from the outset is not bound, which shows that silence counts as acceptance

**Answer:** B. Custom is formed by a general practice of states accepted as law, not by signature; C. Consent in international law may be tacit, expressed through conduct over time; D. A state that objects consistently and from the outset is not bound, which shows that silence counts as acceptance

**Why:** The persistent objector rule is the sharpest evidence. If silence did not count as acceptance, there would be no need for a doctrine protecting the state that speaks up, and the fact that the objection must be consistent and from the outset shows the system treating a failure to object as a form of consent.

Page: https://tryals.app/practice/law-i/the-international-legal-order/why-can-a-rule-of-customary-international-law-bind-a-state-that-has

### 4. Complete the vocabulary of the international order.

**Answer:** A general practice becomes custom only when states follow it out of a sense of legal obligation, which is called **opinio juris**. A treaty conflicting with a peremptory norm from which no derogation is permitted is void, that norm being **ius cogens**. The position that international and domestic law are two separate orders, so that reception is needed, is **dualism**. Under Article 96.1 of the Constitution a treaty enters the internal order once it has been officially **published** in Spain.

**Why:** The last blank is the one to be precise about. **Ratification** is how Spain consents to be bound internationally; **publication** is what brings the treaty into the internal order so that a Spanish court can apply it to a private party. Both are needed, and they do different jobs.

Page: https://tryals.app/practice/law-i/the-international-legal-order/complete-the-vocabulary-of-the-international-order

### 5. The lex mercatoria draws its binding force from the statutes of the states whose traders use it.

**Answer:** False

**Why:** **False**, and that is what makes it interesting. Standard trade terms, model contracts and uniform principles are drawn up by private and technical bodies; they operate because traders adopt them and arbitrators apply them. Whether that makes them law is genuinely disputed, they pass the realist test and fail the formal one.

Page: https://tryals.app/practice/law-i/the-international-legal-order/the-lex-mercatoria-draws-its-binding-force-from-the-statutes-of-the

### 6. A norm of ius cogens is distinguished from an ordinary treaty obligation by its peremptory character. What legal consequence follows when states sign an agreement that breaches such a norm?

A. The entire conflicting agreement becomes void
B. The agreement is valid until a court cancels it
C. The offending clause is replaced by custom norm
D. The treaty remains binding only on signatories

**Answer:** A. The entire conflicting agreement becomes void

**Why:** Peremptory norms override state consent entirely, rendering conflicting agreements void ab initio rather than merely voidable or modified, illustrating how non-derogable standards limit decentralised law-making.

Page: https://tryals.app/practice/law-i/the-international-legal-order/a-norm-of-ius-cogens-is-distinguished-from-an-ordinary-treaty

### 7. Arrange these international instruments in the order they were adopted.

**Answer:**

1. The Charter of the United Nations, 1945
2. The Universal Declaration of Human Rights, 1948
3. The European Convention on Human Rights, 1950
4. The Vienna Convention on the Law of Treaties, 1969
5. The Rome Statute of the International Criminal Court, 1998

**Why:** The compression of the first three is the historical point: the architecture of the post-war order was drafted in five years by people who had just watched it fail. Note also that the Universal Declaration was adopted as a declaration and not a treaty, which is why so much argument since has been about how much of it has since become custom.

Page: https://tryals.app/practice/law-i/the-international-legal-order/arrange-these-international-instruments-in-the-order-they-were

### 8. How many member states does the United Nations have?

**Answer:** 193 (within ±5)

**Why:** **193.** Set that against the roughly two hundred entities usually described as states and you have the measure of how contested the margin is. Membership is not the same as statehood, and several entities that satisfy the usual criteria are not members, which is why counting states is a political exercise dressed as an arithmetical one.

Page: https://tryals.app/practice/law-i/the-international-legal-order/how-many-member-states-does-the-united-nations-have