According to Article 51 of the UN Charter, states have the right to self-defence[1] only if an armed attack occurs. However, some states argue that if an attack is imminent and unavoidable, they can strike first to protect themselves and this is known as pre-emption[2] self-defence. On May 7, 2025, India began a forceful military action known as “Operation Sindoor”[3] in retaliation for the Pahalgam terrorist attack, which killed 26 people. The operation’s goal was to destroy infrastructure associated with organisations like as Lashkar-e-Taiba and Jaish-e-Mohammad by targeting nine terrorist camps in Pakistan and Pakistan-administered Kashmir.
From the perspective of international law, India’s actions might be seen via the preemptive self-defence lens. Even if self-defence against armed assaults is permitted by Article 51 of the UN Charter, India affirmed its right to defend its citizens by defending Operation Sindoor as a vital move to thwart more terrorist activities coming from over the border. Therefore, the paper aims to evaluate the legal limits of Indian forces’ military activity on May 7, 2025, as well as the preemptive self-defence.
BACKGROUND
Since 1945, when the United Nations Charter[4] was signed, the way that war and combat are fought, as well as the adversaries that oppose it, have changed. Nuclear weapons in particular have the capacity to cause irreparable harm to a small nation. Thanks to swift technological advancements, such weapons may now be delivered silently and swiftly, removing the chance of satisfying defence once the button is pressed or the attack is initiated.
Furthermore, the threat posed by non-state actors was not anticipated by the UN Charter’s drafters, who were focused on interstate wars. States that are weak or have fallen have offered a refuge for the development of terrorist groups, so altering the nature of international combat.
In contrast to a state, a terrorist group does not always have a territory or a populace to defend. International law is irrelevant to it. A legal framework for self-defence that enables nations to effectively defend themselves is necessary in light of the risks posed by terrorism.[5]
States have been pushing the limits of when using force in self-defence for at least 60 years as a result of these advances of new and more deadly dangers.The use of force is forbidden by Article 2(4) of the UN Charter. This ban has two exceptions: self-defence permitted by the UNSC, as outlined in UN Charter Chapter VII, and self-defence permitted under Article 51. As In the Nicaragua Case, the International Court of Justice (ICJ) declared that customary international law standards can coexist with those of the UN Charter and confer the same rights and duties.
States’ habit of taking preventative measures against threats from non-state entities and other states as though doing so would fall under Article 51[6] of the UN Charter. It is important to consider whether such acts have established a new standard in customary international law [7]that permits preemptive self-defence as a valid form of self-defence.
LAW AND PRE-EMPTION
The right to self-defence is the oldest law and has existed both practically and figuratively throughout human history. Following the conclusion of World War I[8], it began to be expressed literally in treaty legislation.
The right to “legitimate defence” was explicitly recognised and embraced by the Locarno Pact of 1925. Later, it was also brought up in the 1928 Kellogg-Briand Pact, in which US Secretary of State Kellogg stressed the “inherent” nature of the right to self-defence in its commentary.The “inherent right of self-defence” was included into treaty law by the United Nations Charter’s authors in recognition of the customary significance of self-defence.
In the Nicaragua case, the International Court of Justice (ICJ) also pointed out that the use of the word “inherent” in Article 51 of the Charter is really an attempt to combine customary and treaty law in order to demonstrate the significance of customs to treaty law in the context of self-defence.
PRINCIPLES OF SELF-DEFENCE
Under international law, the use of force or violence is exempted by the concept of self-defence. The term “if an armed attack Occurs…” is used in Article 51 of the United Nations Charter.[9]
According to a literal interpretation, using violence for self-defence requires an armed attack beforehand.
In accordance with customary international law, each nation has the right to self-defence,yet, in reality, this right is not always upheld.
It is said that “It was only as restrictions were imposed on the employment of force by states that the need to articulate the concept of self-defence in international law[10] Become more acute.”
International law still requires the self-defence principle. Moreover, “The conditions that permitted the use of self-defence were expressed in the now-famous communication of the US [11]Secretary of State Webster to the British Government in the wake of the Caroline incident[12].
In other words, the case gave rise to performance metrics for Caroline Ship self-defence, like the views Webster gave to the British Government in the case, which are as follows:
Secretary Webster stressed in his letter that the British government’s defensive effort could only succeed if its actions were supported by “the necessity of self-defence.”
The necessity of self-defence has to be shown to be “immediate, overwhelming, leaving no choice of means, and no moment for deliberation.” The conduct, which was justified by the need for self-defence, had to be constrained by that need and maintained clearly within it, thus Britain also had to demonstrate that the Canadian authorities had not done anything “unreasonable or excessive.”
Webster underlined that justifications for self-defence must be reasonable in light of the requirements, which include being prompt, exceptional, depriving of any other options, and having no time to listen.
Violent incidents against ships Caroline demonstrate that self-defence is appropriate when it is done in a way that is reasonable and restricted to what is necessary for self-defence. Thus, “to summarise, the exercise of force in self-defense was justified under international customary law provided that need for it was:”
1. Instant
2. Overwhelming
3. Immediate
4. And there was no viable alternative action which could be taken.
Perform acts of self-defense must meet the four elements, with the intention[13] that the act of self-defense because really been an attack or the threat of an approaching attack.
THE UNITED NATIONS CHARTER
The United Nations Charter[14] (henceforth referred to as the Charter) came into effect on October 24, 1945. Since then, the legal foundation for the application of force in international law has been established by the Charter. Nearly every state has ratified the Charter. The Charter’s Preamble declares our resolve to protect future generations from the horrors of war, to practise tolerance and coexist peacefully as a good neighbourhood, to pool our resources to uphold global peace and security, and to guarantee “that armed force shall not be used, save in the common interest.”
According to the United Nations Charter, maintaining international peace and security requires that effective collective measures be taken to prevent and eliminate threats to the peace, suppress acts of aggression, and prevent other breaches of the peace. It also calls for the peaceful resolution of international disputes[15] or situations that could result in a breach of the peace, while adhering to the principles of justice and international law.
The United Nations Charter states that all members must resolve their international conflicts amicably so as not to jeopardise global justice, peace, and security. In their interactions with other nations, all members must abstain from threatening or using force against any state’s political independence or territorial integrity, or in any other way that goes against the goals of the UN. in the United States v. Nicaragua case. Article 2(4) is a peremptory norm of international law that states cannot deviate from, according to the International Court of Justice (ICJ).[16]
Thus, the effect of Articles 2 (3) and 2 (4) is that the use of force can only be justified as expressly provided under the Charter[17], and only in situations where it is consistent with the UN’s purposes.
THE RIGHT TO SELF-DEFENCE UNDER THE UN CHARTER
The use of force by one state against another is forbidden under Article 2(4)[18]respectively. This norm makes up the fundamental rule of public international law. Because of the language used in Article 2(4), attempts have been made to limit its application. It also permits the use of force “in any other manner inconsistent with the purposes of the UN,” “against the territorial integrity,[19]” or “against the political independence.” This argument states that acts that do not violate Article 2(4) of the UN Charter or target one of these legally protected rights are not subject to the ban on the use of force. The ICJ dismissed this line of reasoning in the Corfu Channel case.
The fundamental right to individual or collective self-defence in the event of an armed assault on a person must not be compromised by anything in the current Charter.
Member of the UN until the Security Council has taken the required actions to preserve world peace and security. The Security Council’s authority and responsibility under the current Charter to take any action it deems necessary to maintain or restore international peace and security shall not be in any way affected by measures taken by Members in the exercise of this right of self-defence, rather they must be reported to the Security Council immediately.
WHAT CONSTITUTES AN ARMED ATTACK UNDER THE UN CHARTER?
The United Nations Charter states, among other things, that an armed attack include assaults on the State’s airspace[20], territorial sea, and other territory, as well as attacks against the State’s military forces or foreign embassies.
Two schools of thought are distinguished by proponents of the enlarged perspective as to why an armed strike should take into account immediate threats.
First, it should be mentioned that following the UN Charter’s ratification, the inalienable right to self-defense—which was recognised by customary international law and permitted the use of force against an immediate threat—persisted. It is said that the drafters of the UN Charter intended to protect or even codify the inherent right to self-defence that was already in place at the time, rather than to abolish it.
Second, academics contend that the idea of an armed attack is evolving. The use of more deadly weaponry and innovative fighting techniques necessitates that self-defence be extended beyond armed assault. It ought to be modified to fit the new situations when force is used. It would be irrational to demand that a state endure a catastrophic onslaught before using its right to self-defence.
LEGALITY OF ANTICIPATORY SELF-DEFENCE AND MOVING TO PRE-EMPTIVE SELF-DEFENCE
The legality of anticipatory[21] self-defence is related to the right to self-defense’s dual customary charter character, which includes state practice and an evaluation of the Caroline incident principles of necessity, immediacy, and proportionality. The former was covered in the first sub-chapter. Let’s now discuss the latter criterion.
It is important to remember that states have not provided a clear definition or severely limited the right to self-defence. States’ willingness to keep the option to use force for self-defence intact and provide themselves the opportunity to do so might have determined this. However, nations have compromised their own boundaries in the process.
After the Nicaragua case, the ICJ[22] once more limited its discussion to the issue of “imminent threat” in Democratic Republic of Congo v. Uganda (2005). In order to prevent the parties bringing up the matter, the court invoked the well-established Nicaragua case strategy[23]. The primary justification for the court’s avoidance of the “imminent threat” issue is that it is the central contention in the ongoing fight on terror.
The terms “anticipatory” and “pre-emptive” assault should be strictly distinguished from one another right away. These two ideas are frequently used interchangeably to describe preventative attacks in research studies. This mindset is incorrect, though, because the concepts are not interchangeable. Military action against an immediate threat is referred to as a “anticipatory” strike, but a reaction to a threat that is further distant in time is referred to as a “preemptive” attack. It is important to keep this rigid line in mind when addressing the primary topic of this article, which is whether it is legitimate to launch a preemptive strike against nations that host terrorists.
OTHER LAWS RELATED TO PRE-EMPTIVE SELF DEFENCE
- Additional legislation, including the Caroline Doctrine[24] of 1837, which essentially resulted from a diplomatic dispute between the United States and British Canada. Created the anticipatory self-defence standards that are still used in international law.
In this case, it was decided that the threat had to be immediate, overpowering, and devoid of any time for deliberation or other options.
Anticipatory self-defence is allowed by this philosophy, but only under very specific circumstances. - Another is the 1974 resolution of the General Assembly,[25] which attempted to define what an act of aggression is. In essence, it emphasised the definition of aggression as the use of force that violates the charter. Here Preemption strikes were considered aggressive unless they were permitted under Article 51.
- Jus and bellum,[26] which is essentially a body that establishes the circumstances in which a state may employ force or declare war. Because some reasons supported anticipatory self-defence and others opposed it, this topic is up for dispute.
- The bush doctrine, [27]which strongly supported preemptive self-defence, is the final one. It affirmed the right to use force to stop new threats, particularly those posed by rogue nations and terrorism. However, international law does not generally accept this. Critics contend that it violates the UN charter and may result in the self-defence clause being abused.
INDIAN LAWS FOR THE CONCEPT OF PRE-EMPTION
Preemptive self-defence is implicitly accepted under the Bhartiya Nyaya Sanhita 2023’s broader right to private defence, even though it is not expressly defined in Indian law. This is especially true in circumstances when there is a legitimate fear of danger.
According to Section 35 of the BNS 2023, nothing done in the exercise of the right to private defence of one’s person or property constitutes a crime.
The extent of the right to self-defence is described in Section 36, which states that it must be used when one’s own property or another person’s body is under danger. However, it restricts the authority by stating that only necessary and reasonable force may be used to exercise this right.
Section 37 addresses when this right to self-defence starts, stating that it starts as soon as there is a legitimate fear of harm to one’s life or property.
Judicial interpretations
- Darsan singh vs state of Punjab 2010[28]
The Supreme Court decided in this instance that one does not have to wait to be assaulted. Preemptive self-defence is warranted if there is a sincere and reasonable fear of harm.
- State of UP vs Ram Swarup[29]
In this case, the court ruled that self-defence is permitted in situations when there is a genuine threat, even in the absence of an actual attack.
Limitations and restrictions
- When there is time to approach the authorities.
- Against public servants acting lawfully.
- When the use of the force is grossly excessive.
- When apprehension is unreasonable or imaginary.
In accordance with natural justice and constitutional principles, the Bhartiya Nyaya Sanhita 2023 upholds the Indian legal heritage of the right to private defence as well as the right to preventative self-defence. Although not specifically referred to as preemptive self-defence, the idea is included into the law that permits defences based on a reasonable fear of danger.
THE OPERATION SINDOOR AND INDIA’S VIEWS TO DEFEND IT UNDER PRE-EMPTIVE LAWS
India started Operation Sindoor on May 7, 2025, as a major military reaction to the terrorist incident in Pahalgam, Jammu and Kashmir, on April 22. According to reports, Indian soldiers carried out Operation Sindoor, a targeted military operation, to eliminate an immediate danger. The administration defended it by saying it was a necessary and appropriate reaction to intelligence reports that a large-scale strike was imminent.
Legally speaking, every proactive self-defence action must meet the Caroline test [30]of proportionality and necessity. According to need, the danger must be present at all times and be so great that there is no time for consideration or choice of methods. According to proportionality, the amount of force employed must match the danger.
Operation Sindoor involved premeditated mass casualty assaults, which made necessity and proportionality necessary.
The fact that Operation Sindoor was carried out in or close to Pakistan’s border region adds difficulty because any use of force across international borders without the host state’s approval may be interpreted as a violation of its territorial sovereignty.
In the DRC v. Uganda case[31], the International Court of Justice (ICJ)[32] stressed that even in cases of cross-border terrorist attacks, the victim must show that the host state is incapable or unwilling to contain the threat and that the response complies with stringent requirements for necessity and proportionality.
Under this standard, India’s claim that Pakistan harbours and aids terrorist organisations would make its case stronger.
CONCLUSION
India’s strategic use of proactive self-defence against changing security threats is exemplified by Operation Sindoor. Even if anticipatory strikes are still unclear under international law, such acts show how important it is to review existing legal frameworks. Legitimising preemption in international counterterrorism initiatives requires striking a balance between state sovereignty and new security realities.
[1] the use of force to protect yourself or your property
[2] Preventing something from happening
[3] The 2025 India–Pakistan conflict was a brief armed conflict between India and Pakistan that began on 7 May 2025, after India launched missile strikes on Pakistan, codenamed Operation Sindoor.
[4] The United Nations charter 1945.
[5] According to the Oxford Learner’s Dictionaries, terrorism is the use of violent action to achieve political aims or to force a government to act.
[6] Article 51 of the United Nations Charter 1945.
[7] Customary international law arises from the consistent practice of states, where they treat certain actions as obligatory due to their sense of legal obligation. It’s a form of international law that is not based on written treaties or conventions, but rather on established practices and the belief that those practices are legally binding.
[8] World war 1, 1914
[9] United Nations Charter 1945
[10] International law, also known as the “law of nations,” is a body of legal rules and principles that govern the relations between sovereign states and other entities recognized as international actors, according to Britannica.
[11] United States
[12] Caroline Incident of 1837.
[13] what somebody intends or means to do; a plan or purpose
[14] United Nation Charter 1945
[15] An international dispute is a conflict between countries, often involving disagreements over law, facts, or conflicting interests.
[16] International Court of justice
[17] United Nations Charter 1945
[18] Article 2(4) of the United Nations Charter 1945
[19] Territorial integrity is a principle of international law stating that a state has the right to maintain its borders and the territory within them without outside interference or coercion.
[20] A state’s airspace refers to the three-dimensional space above its land and territorial waters that is under its jurisdiction.
[21] the state of expecting something to happen (and preparing for it)
[22] International Court of Justice
[23] The Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States) case before the International Court of Justice (ICJ) involved Nicaragua’s claim that the United States had violated international law by supporting paramilitary groups (the Contras) and directly attacking Nicaragua.
[24] Caroline case of 1837
[25] Resolution of the general assembly 1974
[26] In international law, “jus” and “bellum” refer to two distinct but related aspects of warfare: “jus ad bellum” and “jus in bello.” “Jus ad bellum” (Latin for “right to war”) defines the conditions under which a state is justified in going to war or using force, while “jus in bello” (Latin for “law in war”) governs the conduct of parties once a war has begun.
[27] The Bush Doctrine holds that enemies of the U.S. use terrorism as a war of ideology against the nation. The responsibility of the United States is to protect itself by promoting democracy where the terrorists are located so as to undermine the basis for terrorist activities.
[28] Darsan singh vs state of Punjab 2010
[29] State of UP vs Ram Swarup 1974
[30] Caroline case 1837
[31] DRC v. Uganda 1999
[32] The International Court of Justice (ICJ) is the principal judicial organ of the United Nations (UN), sometimes referred to as the World Court. It was established in 1945 and is located in The Hague, Netherlands.
Author: Ritu Chaudhary
Juris Centre 