Immunities and other limitations on sovereignty

State sovereignty is not unfettered. Many international rules restrict it. In addition to treaty rules, which of course vary from State to State, limitations are imposed upon State sovereignty by customary rules. They are the natural legal consequence of the obligation to respect the sovereignty of other States.

Rights and immunities of foreign states

A State may not exercise its sovereign powers over, or otherwise interfere with, actions legally performed by foreign States on its territory. This legal inability stems from the general principle imposing respect for the independence and dignity of foreign States (par in parem non habet imperium, that is, equals have no jurisdiction over one another). More generally, a State may not carry out any of the following acts.

1. Call to account on its own territory a foreign State official for acts performed in the exercise of his functions, except hi the case of international-crimes (as was recently restated by the ICTY Appeals Chamber in Blaskic).'

2. Interfere with foreign armed forces lawfully stationed on its territory (unless authorized by treaty rules or ad hoc consent).

3. Perform coercive acts on board a foreign military or public ship or aircraft (for instance, it may not enforce the law there).

4. Submit to the jurisdiction of their courts foreign States for acts performed in their sovereign capacity (the doctrine of the 'sovereign immunity of States'). These doctrines are grounded on a twofold rationale: first, States should not interfere with public acts of foreign sovereign States out of respect for their independence; second, generally speaking and with regard to both domestic decisions and decisions made by foreign countries, the judiciary should not interfere with the conduct of foreign policy, by either national or foreign governmental authorities, on the principle of separation of powers. It follows that it is not for courts, but for the organs responsible for foreign affairs, to take matters relating to foreign acts into their hands and use diplomatic channels to discuss, or argue over, them with the foreign State concerned.

(5) Seize foreign State property or take any other measure of execution or preventive measure against the property of a foreign State intended for use for the discharge of public functions. In contrast, measures of constraint may be taken against property or assets destined for a private function, that is, intended for use for commercial purposes.

NON-INTERVENTION IN THE INTERNAL OR EXTERNAL AFFAIRS OF OTHER STATES

General

The principle of non-intervention in the affairs of other States also belongs to the old pattern of the world community.

Since the period of classical international law the principle has been concretely enshrined in a few specific customary rules.

The first one is the rule prohibiting a State from interfering in the internal organization of a foreign State. For instance, one State may not decide winch organ of a foreign State is competent to perform a certain act, nor may it enjoin a foreign State agent to discharge certain activities or accomplish a certain act. Another rule prohibits sites from encroaching upon the internal affairs of other States. Thus for instance a State is not allowed to bring pressure to bear on specific national bodies of other countries (the legislature, enforcement agencies, or the judiciary), nor may it interfere in the relations between foreign government authorities and their own nationals. Yet another rule enjoins States to refrain from instigating, organizing, or officially supporting the organization on their territory of activities prejudicial to foreign countries.

Another customary rule has a more specific purport, in that it deals only with civil strife: it stipulates that whenever a civil war breaks out in a foreign country, States are duty-bound to refrain from assisting insurgents, unless they qualify for the status of national liberation movements.

These rules are still in force.