Retorsion and Reprisals are the tools of Settlement of International disputes. It comes under compulsive or coercive means of settlement. The term dispute means a disagreement on a point of law or fact, a conflict of legal views or of interests between two persons.

The expression International disputes has a wider connotation, that covers within its ambit inter-state disputes as well as disputes between states and individuals, corporate bodies and non-state entities which are also subject to international regulations. But the discussion here is confined primarily to inter-state disputes. If remain unresolved, they may threaten international peace and security. To settle these disputes, international law embodies certain rules and procedures springing partly out of customs or usages and partly out of treaties or conventions.

States resort to compulsive means of settlement when they cannot agree to or fail to settle their disputes by peaceful means. Such means involve some amount of compulsion or coercion, and if necessary, also the use of force to make the reluctant state to agree to a settlement.

When there is use of force involved, their legality is questionable under Art. 2(4), of the United Nations Charter, but due to the weaknesses of the present international law without any centralised machinery to settle international disputes, these measures continue to have their relevance in international relations. They are the forms of self-help. These measures include retorsion, reprisals, embargo, pacific blockade and intervention. These measures are short of a state of war. War is also one of the compulsive means.

But there is difference between war and other means as follows:

1. In measures other than war, the relations of peace, diplomacy, security and others are maintained, in war they may come to an end.
2. The compulsive means are confined to certain harmful measures only, in war any amount and any kind of force can be used, subject to humanitarian law.
3. As soon as the other state is willing to settle the difference, the measure must cease, but it is not so in war, which comes to an end with the defeat of one of them.[1]

Retorsion
Retortion is a retaliatory measure, it is relied on the principle of Tit for Tat.[2] This act is performed by a state against another in an unfriendly, discourteous or inequitable manner. These acts are of the similar nature as those taken by the offending state. Such acts performed by the states are permitted and are legal and justified under International Law.

For example, if a state imposes restrictions on the entry of citizens of a particular country in its territory, that country may also impose similar restrictions, or if State A declares persona non grata i.e., an unwelcome person, the ambassador of State B, that can declare similarly in respect of the ambassador of State A. The method of implementing retorsion may seem as an inappropriate way but it is an effective tool of Settlement of International disputes. Retorsion has been applied as a means to settle disputes within the states in plethora of cases. The legal implementation of retorsion has been affected to a great extent by the UN Charter.

Retaliatory actions such as severance of diplomatic or economic ties, or withdrawal of diplomatic or consular privileges or withdrawal of fiscal concessions are the forms of unfriendly acts, which are seemingly legal and are not circumscribed by the international law but actions which endangers the ‘International Peace, Security and Justice’ that cannot be legally taken in any circumstances. If such acts taken, it will would be treated as illegal and not be justiciable under the United Nations Charter which requires members to settle their disputes by peaceful means.[3]

Reprisal
Reprisals are retributive or punitive in nature. In case of any disputes or issues are not resolved by Retorsion, the states have the rights to resort to Reprisal. They are adopted by a state to seek redress from another state for its illegal or unjustified acts. The aim of reprisal is to punish the recalcitrant state, and to compel the delinquent state to discontinue the unlawful or wrongful act and compensate the state wronged.

Reprisals are injurious or otherwise internationally illegal acts of one state against another and are exceptionally permitted for the purpose of compelling the latter to consent to a satisfactory settlement of a dispute created by its own international delinquency. The delinquent act could be the violation of the dignity of a foreign State, its territorial supremacy, or the non-compliance with treaty obligations.

Reprisals may be performed against anything and everything that belongs to or is due to the delinquent State or its citizens. Earlier, reprisal involved the seizing of property or persons but later it included any coercive measure adopted by a state to seek redress from the offending state. Reprisals may take various forms, such as an embargo of the offending State's ships, seizure of its property on the high seas, economic sanction or boycott of its goods, bombardment or even pacific blockade.

But the peace-time reprisals are different from reprisal actions taken by a state during war, whose object is generally to force an opponent state to stop breaking the laws of war. The right to resort to forcible reprisals has always remained controversial. Although the law is unsettled in this respect, such acts must satisfy certain conditions, but to be valid.[4]

Difference Between Retorsion and Reprisal

Retorsion	Reprisal
Retortion is retaliatory in nature.	Reprisals are retributive or punitive in nature.
In retorsion action taken by the aggrieved state is apparently legal to which no objection can be taken.	In reprisals, the action taken by the aggrieved state is not always true and they may be contrary to international law and illegal.
Retorsion is resorted against the inequitable and unfriendly act of another state.	Reprisals is actuated by the illegal act of the delinquent state.
In retorsion there is no use of force. It involves discourteous or inappropriate manner.	Reprisals generally involves the use of force its legality is questionable under International Law.

Naulilaa Case, (Germany V. Portugal)[5]

Facts:

1. The incident occurred in 1915, a German group entered Naulilaa, a Portuguese post on the frontier of Angola and the then German South-West Africa.
2. Due to misunderstanding, three Germans were killed. As a measure of reprisal, the Governor of South-West Africa sent a military expedition to the Portuguese territory, which attacked several Portuguese posts and drove out the garrison from Naulilaa.
3. In the regions which Portuguese were forced to vacate, a local uprising took place after the Germans returned to South-West Africa. The suppression of the local uprising caused great harm to Portugal which expelled the German counsel from its country as a reprisal and demanded compensation.
4. Germany took the plea of legitimate reprisal before the tribunal.

Issue: Was the attack of Germany are justified?[6]

Observation:
The tribunal observed that reprisals are acts of self-help and they seek to impose on the offending state reparation for the offence, the return to legality and the avoidance of new offences. They are limited by considerations of humanity and the rules of good faith, applicable in the relations between States.

The tribunal laid down three conditions of legitimacy of reprisals:

1. Reprisals are illegal unless they are based upon a previous act contrary to international law.
2. They must be preceded by an unsuccessful demand of redress. In fact, the necessity of resorting to force is justified if the possibility of obtaining redress by other means fails.
3. The measure adopted should be proportionate in relation to the injury suffered or provocation received.

Held:

1. The Tribunal found Germany guilty of using excessive force, without first requesting for a redressal, and the Portuguese act not contrary to international law.
2. Germany was held liable to pay compensation for its unjustified act.[7]

Conclusion
Retortion means retaliation, it is relied on the principle of Tit for Tat. This act is done by a state against another in an unfriendly, discourteous or inequitable manner. Such acts performed by the states are permitted. They are legal and justified under International Law. Implementation of retorsion may seem as an inappropriate way but it is an effective tool of Settlement of International disputes.

Reprisals are retributive or punitive in nature. They are adopted by a state to seek redress from another state for its illegal or unjustified acts. The aim of reprisal is to punish the recalcitrant state, and to discontinue the unlawful or wrongful act. It is actuated by the illegal act of the delinquent state. Earlier, reprisal involved the seizing of property or persons but later it included any coercive measure adopted by a state to seek redress from the offending state. The right to resort to forcible reprisals has always remained controversial and since it generally involves use of force its legality is questionable under International Law.

References:

1. Joycee, Naulilaa case, https://www.scribd.com/document/349001305/Naulilaa-Case
2. Rachit Garg, Public International Law, https://blog.ipleaders.in/international-law/#Compulsive_or_coercive_means
3. S.K Verma, Public International Law E-Book pdf, Page no. 479-482

End-Notes:

1. S.K Verma, Public International Law E-Book pdf, Page no. 479
2. Rachit Garg, Public International Law, https://blog.ipleaders.in/international-law/#Compulsive_or_coercive_means
3. S.K Verma, Public International Law E-Book pdf, Page no. 479- 480
4. S.K Verma, Public International Law E-Book pdf, Page no. 481-482
5. 1928 2 RIAA 1011
6. Joycee, Naulilaa case, https://www.scribd.com/document/349001305/Naulilaa-Case
7. S.K Verma, Public International Law E-Book pdf, Page no. 482