international law 2026

What seventeenth-century event is usually said to mark the beginning of modern international law?

The 1648 Peace of Westphalia, which ended the Thirty Years War and established the modern state system.

The 1648 Peace of Westphalia, which ended the Thirty Years War and established the modern state system.

Hugo Grotius.

What legal principle did Hugo Grotius champion to benefit Dutch trading interests by ensuring free shipping?

The freedom of the seas.

In early international law, what was the term for territory considered to belong to no one, allowing European powers to claim it?

Terra nullius.

In contrast to 'terra nullius', Grotius argued in 'Mare Liberum' that the high seas were _____, meaning common property not susceptible to sovereignty.

terra communis

According to John Austin's 19th-century positivist view, international law is not truly law but rather what?

Positive morality.

What is the term for a state's lawful but unfriendly act taken in response to another state's action, such as recalling an ambassador?

Retorsion.

What is the modern term for reprisals, which are acts that are normally illegal but become lawful when taken in response to a prior illegal act by another state?

Countermeasures.

Which international relations theory views international law as largely irrelevant, asserting that states are primarily motivated by a struggle for power?

Realism.

Which international relations theory suggests that international law can be relevant if designed to account for states' self-interest, helping to facilitate cooperation?

Liberal institutionalism.

What is the term for the exercise of authority on a global level outside of regular legal structures, posing a challenge to traditional international law?

Global governance.

What is the Latin term for peremptory norms of international law from which no derogation is permitted, such as the prohibition of genocide?

Jus cogens.

What foundational case laid down the idea that international law is a permissive system, where state behavior is permitted unless explicitly prohibited?

The Lotus case (1927).

According to Article 38 of the ICJ Statute, what are the primary sources of international law?

International conventions (treaties), international custom, and the general principles of law recognized by civilized nations.

What 1969 convention codified the customary rules on the creation, effects, validity, and termination of treaties between states?

The Vienna Convention on the Law of Treaties (VCLT).

What are the two main components required to establish a rule of customary international law?

A general practice (state practice) and its acceptance as law (opinio juris).

What is the concept of a 'persistent objector' in customary international law?

A state that has persistently objected to a developing rule of customary law is not bound by that rule once it is established.

Concept: Opinio juris

Definition: The subjective belief held by states that their practice is legally required, which distinguishes binding customary law from mere habit or etiquette.

What is the primary function of 'general principles of law' as a source of international law?

To fill gaps in the law where there is no applicable treaty or rule of customary law.

What landmark cases established that unilateral declarations by states can have legally binding effect?

The Nuclear Tests cases (Australia v. France; New Zealand v. France).

What is the term for normative utterances that do not fit neatly into the traditional sources of law, often referred to as non-legally binding agreements?

Soft law.

According to the VCLT, a 'treaty' is an international agreement concluded between States in written form and _____.

governed by international law

What is the legal significance of a signature on a treaty that is subject to ratification?

It signifies agreement on the text and creates an interim obligation not to defeat the object and purpose of the treaty.

Concept: Reservation (to a treaty)

Definition: A unilateral statement made by a state when signing or ratifying a treaty, whereby it purports to exclude or modify the legal effect of certain provisions in their application to that state.

What is the key test established by the ICJ in the Reservations to the Genocide Convention case for determining the permissibility of a reservation?

The 'object and purpose' test, which states that a reservation is permissible as long as it is not incompatible with the object and purpose of the treaty.

Under Article 20(5) of the VCLT, what happens if a state does not react to a proposed reservation within twelve months?

The state is considered to have accepted the proposed reservation.

What are the three main traditional methods of treaty interpretation?

The textual approach, the historical approach, and the teleological (object and purpose) approach.

Which approach to treaty interpretation does the VCLT prioritize in Article 31?

A compromise between the textual and teleological approaches, interpreting terms in their context and in light of the treaty's object and purpose.

The historical records of treaty negotiations, known as _____, are considered a supplementary means of interpretation under the VCLT.

travaux préparatoires

According to Article 103 of the UN Charter, what happens in a conflict between a member's obligations under the Charter and other international agreements?

Obligations under the UN Charter shall prevail.

What is the only factor related to the substance of a treaty that can render it automatically invalid under the VCLT?

Conflict with a peremptory norm of general international law (jus cogens).

Under the VCLT, what type of breach of a treaty allows the other party to invoke it as a ground for termination?

A material breach.

What legal doctrine allows for the termination of a treaty due to a fundamental, unforeseen change of circumstances?

Rebus sic stantibus (VCLT Article 62).

What are the four criteria for statehood as defined by the 1933 Montevideo Convention?

A defined territory, a permanent population, an effective government, and the capacity to enter into relations with other states.

The _____ theory of recognition holds that an entity becomes a state by meeting the legal criteria, and recognition by other states is merely a political acknowledgment of this fact.

declaratory

The _____ theory of recognition holds that an entity is not a state in international law until it has been recognized as such by other states.

constitutive

What does admission to the United Nations signify in terms of statehood?

It is considered to be something akin to collective recognition, marking the entity as a legitimate member of the community of states.

What principle, often applied in decolonization, holds that former internal administrative boundaries become international boundaries upon independence?

Uti possidetis.

In the context of acquiring territory, what mode involves the peaceful transfer of territory from one sovereign to another, often by treaty?

Cession.

What is the 'clean slate' principle regarding state succession and treaties?

It is the presumption that a newly independent state is not bound by the treaties concluded by its predecessor.

What is the major exception to the 'clean slate' principle in state succession?

Human rights treaties and boundary treaties are generally considered to continue to bind the successor state.

How is membership in most international organizations affected by state succession?

Membership is considered personal, so a new state must apply for admission on its own behalf.

As confirmed by the ICJ in the 1949 Reparation opinion, international organizations are considered _____ of international law.

subjects

What is the term for the legal powers of an international organization that are not explicitly stated in its constituent treaty but are inferred as necessary for it to fulfill its purpose?

Implied powers.

Which principal organ of the UN is its plenary body, where all 193 member states are represented?

The General Assembly.

Which principal organ of the UN is its executive body, responsible for maintaining international peace and security and composed of 15 members?

The Security Council.

What is the primary characteristic that distinguishes a non-governmental organization (NGO) from an international organization like the UN?

NGOs are private organizations, not created by states through intergovernmental treaties.

What are circumstances that may remove the wrongfulness of an act that would otherwise be a breach of international law?

Circumstances precluding wrongfulness.

According to the table of contents, Chapter 8 on International Courts and Tribunals discusses what two main methods for formally settling disputes?

Arbitration and Adjudication.

What is the principal judicial organ of the United Nations?

The International Court of Justice (ICJ).

What are 'interim measures of protection' in the context of the ICJ?

Provisional orders issued by the Court to preserve the respective rights of either party pending a final decision.

What type of non-contentious proceeding allows certain UN organs and specialized agencies to request the ICJ's guidance on a legal question?

Advisory opinions.

In the context of the European Convention on Human Rights (ECHR), which theory posits that great powers promote human rights regimes to coerce weaker states?

Realist theory.

The _____ theory argues that altruistic governments and transnational groups in established democracies promote human rights norms out of a sense of moral purpose.

ideational

According to Andrew Moravcsik's 'republican liberal' theory, what was the primary motivation for newly established democracies to support the ECHR?

To 'lock in' their fragile democratic institutions against potential domestic, non-democratic threats.

In the negotiations for the ECHR, what was the general position of established democracies like the United Kingdom?

They supported declaratory norms but opposed reciprocally binding enforcement mechanisms like compulsory jurisdiction and individual petition.

Why were established democracies, according to republican liberal theory, less inclined to support binding international human rights enforcement?

Their democratic institutions were already stable, so they feared the sovereignty costs of external oversight without perceiving a domestic benefit.

According to British domestic deliberations, what was the primary fear regarding adherence to the ECHR?

The 'grave apprehension' that the convention would threaten idiosyncratic domestic political practices and undermine parliamentary sovereignty.