Rights that cannot under any circumstances be waived or interfered with.
There are different ways for states to (attempt to) acquire new territory. Accretion is a mode of acquiring territory, whereby new land is created naturally, for example through volcanic eruptions, as in the case of the island of Surtsey, Iceland (1963). Such naturally formed land becomes part of the state in whose territory or territorial waters it arises.
By contrast, man-made additions – sometimes called artificial accretion – do not create territorial rights under international law; for instance, artificial islands constructed in the South China Sea cannot generate new sovereign territory.
Accretion is the opposite of erosion, where land gradually disappears due to natural forces. It must also be distinguished from avulsion, which involves sudden or violent geographical changes (e.g. through earthquakes). Importantly, only gradual changes due to accretion can shift international boundary lines between states.
Jure gestionis actions are of a commercial nature. Such actions performed by a state do not enjoy immunity. A jure gestionis action can, for example, involve the leasing of real estate.
Jure imperii actions are actions performed by the state and diplomats (or other state representatives). Such actions enjoy immunity, meaning the state cannot be held accountable in a foreign state’s court. However, it is possible to assert a claim for compensation in the courts of the state that violated international law. A jure imperii action can include legislation, taxation, or foreign policy-related actions.
A state has the right to exercise self-defence, even if an attack has not yet occurred. This is called anticipated self-defence and requires that an attack is imminent.
The baseline is the line from which the breadth of the territorial sea and other maritime zones is measured; normally it follows the low-water line along the coast, but straight or archipelagic baselines may be used in specific geographical situations.
A treaty concluded between two states.
There are different ways for states to (attempt to) acquire new territory. Cession is a mode of acquiring territory, whereby one state voluntarily transfers sovereignty over a portion of its territory to another state. This transfer usually takes place by treaty and is most often effected through purchase or formal agreement.
A classic example is the United States’ purchase of Alaska from Russia in 1867, as well as the United States’ purchase of the Danish West Indies from Denmark in 1917. Beyond bilateral agreements of this kind, cession was one of the primary methods of colonisation employed by European powers in Africa and Asia during the nineteenth and early twentieth centuries.
Cession may also occur in the context of resolving border disputes between states, where so-called “land swaps” are agreed to stabilise territorial boundaries. Such mechanisms are often discussed in contemporary peace negotiations – some law professors suggest that a potential future final settlement between Israel and Palestine might involve some form of reciprocal cession of land.
The legal foundations of cession are governed by principles akin to those of contract law:
- No greater rights than the ceding state: The acquiring state cannot obtain a stronger or broader title to the territory than that which the ceding state itself possessed.
- Respect for third-party rights: The acquiring state must honour the potential legal rights of third states in relation to the ceded territory.
- Self-determination: In the modern era, any attempted purchase or transfer of territory must take account of the evolution of international law recognising the right of peoples to self-determination, a principle which limits the ability of states to dispose of territory without consideration for its inhabitants.
Civilians are all persons who are not combatants or other members of the armed forces. They enjoy general protection from the dangers of military operations and may not be made the object of attack. This protection is enshrined in Geneva Convention IV and, where applicable, Additional Protocol I (AP I).
However, civilians lose their protection “for such time as they take a direct part in hostilities” (AP I, art. 51(3)). According to the International Committee of the Red Cross (ICRC), direct participation requires three elements: (1) the act must be likely to harm a party’s military operations, capacity, or protected persons/objects; (2) there must be a direct causal link between the act and the expected harm; and (3) the act must be specifically designed to cause such harm in support of one party and to the detriment of another.
Thus, civilians are protected as long as they abstain from direct participation in hostilities, but once they cross that threshold, they may lawfully be targeted for the duration of their involvement.
Combatants are members of the armed forces (including qualifying militias and resistance movements) who are entitled to take a direct part in hostilities. They may lawfully be targeted with lethal force or detained until the end of hostilities, but once rendered hors de combat (e.g. surrendering, captured, unconscious, or severely wounded) they cannot be attacked.
A lawful (privileged) combatant has the right to participate in hostilities, enjoys immunity from prosecution for lawful acts of war, and if captured, is protected as a prisoner of war under Geneva Convention III. An unlawful (unprivileged) combatant is not entitled to combatant’s privilege or ""prisoner of war"" status, may be prosecuted under domestic law, but remains protected under the law of armed conflict.
Concurring (overlapping) jurisdiction arises when two or more states have valid legal grounds to assert jurisdiction over the same act or offence, since multiple principles of prescriptive jurisdiction may apply simultaneously. International law provides no formal hierarchy between such claims, but practice and instruments such as the 2001 Convention on Cybercrime encourage states to consult and determine the most appropriate forum, typically favouring the territorial state as having the closest link. In Barcelona Traction (Separate Opinion, Judge Fitzmaurice), states were urged to exercise moderation and restraint to avoid undue encroachment on another state’s jurisdiction, with approaches like the “rule of reason” used to identify the state with the strongest interest.
There are different ways for states to (attempt to) acquire new territory. Conquest is the forcible acquisition of territory by one state through military action. Conquest, once recognised as a means of acquiring territory, has been prohibited since 1945 with the adoption of the UN Charter. Today, a state cannot obtain legal title through the use of force. When a state's armed forces occupy the territory of another, this triggers the international legal regime of belligerent occupation, which is strictly temporary in character and does not transfer sovereignty.
In such cases, the displaced sovereign loses only de facto possession, while retaining de jure title to the territory. Modern international law is clear that conquest or annexation by force cannot alter territorial status. For instance, the UN General Assembly condemned Russia’s attempted annexation of several Ukrainian provinces in October 2022, declaring it to be without validity under international law. The doctrine is also central to the Israel/Palestine conflict, where questions of occupation and sovereignty remain unresolved.
Ex injuria jus non oritur, derived from Latin, meaning "law does not arise from injustice". The principle asserts that legal rights cannot arise from wrongful conduct. In some cases, the principle can lead to denial of statehood to entities otherwise fulfilling the criteria for statehood, cf. for instance the Northern Cyprus-case, para. 94-95.
Despite controversy, the principle may be overridden under certain circumstances. A notable example of this principle being set aside occured during India's intervention in the 1971 conflict between East Pakistan (now Bangladesh) and West Pakistan. India invaded Pakistan in order to support the Bengali population. This intervention can be viewed as a violation of Pakistan's sovereignty (and thus, a breach of the principle ex injuria jus non oritur). However, moral and humanitarian grounds led to the justification of such a breach. Regardless of the controversy related to India's methods, the intervention resulted in the creation of Bangladesh, which gained international recognition as an independent state.
Hard law refers to legally binding rules and obligations enforceable under international or domestic law (e.g. treaties, statutes, judicial decisions), whereas soft law consists of non-binding instruments (e.g. declarations, guidelines, codes of conduct) that carry political or moral weight but lack formal legal enforceability.
Jurisdiction on the basis of nationality (the active personality principle) is the authority of a state to apply its laws to its own nationals regardless of where they are located, reflecting the state’s legitimate interest in their conduct abroad. It allows a state to prosecute its citizens for crimes committed overseas, and in cases of dual nationality, more than one state may assert jurisdiction. In Nottebohm (ICJ, 1955), the Court emphasised that nationality must represent a genuine connection if it is to be relied upon vis-à-vis other states.
Jurisdiction over aircraft and ships is based on the principle that a state exercises complete and exclusive sovereignty over the airspace above its territory and territorial waters (Chicago Convention, 1944). For aircraft, the state of registration has jurisdiction over offences committed on board while in flight (Tokyo Convention, 1963), which also grants the captain authority to use reasonable force and obliges states to act against hijacking. At sea, the flag state generally has exclusive jurisdiction over vessels on the high seas, subject to specific exceptions under international law (e.g. piracy, slavery, unauthorised broadcasting).
Jurisdiction to prescribe is the authority of a state to legislate and make its laws applicable to persons, property, or conduct, including extraterritorially, provided this is supported by a recognised principle of international law and there exists a sufficient nexus between the conduct and the state’s legitimate interests at the time of the act.
Jurisdiction to prescribe can be sub-categorised as follows:
- territorial jurisdiction,
- jurisdiction on the basis of nationality (the active personality principle),
- the passive personality principle,
- protective jurisdiction,
- universal jurisdiction,
- concurring/overlapping jurisdiction, and
- jurisdiction over aircraft and ships.
Each of the sub-categories listed above are also described as their own term here on Learning Law.
Jus ad bellum deals with rules aimed at preventing armed conflicts. These rules apply in conflicts involving one or more states. The general principle is that a state must not threaten or use force against other states. See the prohibition on the use of force.
Jus cogens, or peremptory norms of general international law, refers to a category of fundamental, overriding principles from which no derogation is permitted. These norms are recognised by the international community of states as norms that are binding on all subjects of international law, irrespective of consent, and prevail over other international obligations. Examples of jus cogens norms include the prohobition of genocide, the prohibition of torture and the prohibition of slavery. The concept of jus cogens is cofified in Article 53 of the Vienna Convention on the Law of Treaties (1969).
Jus in bello governs the relationship between states during armed conflicts. These rules are primarily found in the Geneva Conventions. The purpose of jus in bello is its main rule, which prohibits states from threatening or using force against other states.