Use of Force in International Law | Law Optional Notes for UPSC PDF Download

Introduction 

Law involves a system of authorized force used to uphold and improve public order goals while prohibiting unauthorized coercion. Therefore, law and coercion are not opposing concepts.
In contrast, formal legal structures are not established when there is natural social agreement; they are created when there is disagreement. Those who are more influential within a group impose their interpretation of common interests through the legal system, which includes sanctions. Law recognizes the necessity and inevitability of coercion in social processes but aims to organize, control, and optimize it.
The international legal system differs from these general legal characteristics primarily in the degree of organization and centralization of coercion. In national systems, coercion is organized, relatively centralized, and mostly controlled by the state apparatus. In the international system, this is not the case. Historically, individual actors have retained the right to unilaterally use force to protect and assert their legal rights.

Historical Overview

1815-1945

• During the 19th century in Europe, war was often seen as the last option for resolving disputes. It was considered a characteristic of statehood, and the victor in a war could claim territorial rights. States had the authority to wage war without any internationally agreed-upon rules. The concept of distinguishing between just and unjust wars emerged.
• St. Augustine and St. Thomas Aquinas proposed three criteria for a just war, famously outlined in Summa Theologica:
  • It should be declared by a sovereign authority (prohibiting private wars).
  • It must have a just cause (punishing wrongdoers).
  • A just cause must be accompanied by the right intention.
• As the number of independent states in Europe grew, this doctrine began to change. Wars started to be viewed and defined as legal matters rather than subjective moral judgments. States were no longer in a position to judge whether another state's reasons for using force were just or not.
• This shift was influenced by the rise of positivism, which emphasized sovereignty, and the Peace of Westphalia in 1648, which established the European balance of power system. This system lasted in Europe until the early 20th century and effectively ended with the outbreak of World War I.
• After World War I, efforts were made to rebuild international relations and prevent acts of aggression. The League of Nations (LON) was established in 1919 with the goal of achieving this. According to the Covenant of the League of Nations, member states were required to submit inter-state disputes for arbitration or seek other forms of judicial settlement at the League's Council. However, the Covenant did not completely eliminate the right of states to resort to war; it placed some limitations on this provision.
• In 1928, another attempt to legally regulate the use of force was made through the General Treaty for Renunciation of War as an Instrument of National Policy, commonly known as the Kellogg-Briand Pact. Parties to this treaty denounced the use of war and agreed to renounce it as a tool of national policy in their relations with each other. They also committed to resolving disputes through peaceful means. The Pact had 63 state parties and is still in force today. This pact served as the basis for prosecuting aggressive war at the International Military Tribunals in Nuremberg and Tokyo.
• The Kellogg-Briand Pact was invoked in various conflicts, such as the hostilities between China and the USSR in 1929, the conflict between China and Japan in 1931, and the Leticia dispute between Peru and Ecuador in 1933. The Pact was even cited in 1939 by the League Assembly in condemning Soviet actions against Finland.

Post-1945 Legal Framework: The UN Charter and Its Articles

• The current legal framework governing the use of force in international law is established in the United Nations (UN) Charter. Article 2(4) of the UN Charter is considered a fundamental principle of customary international law and is binding on all states worldwide. It serves as the cornerstone of the UN Charter and was further defined as a principle of international law in the 1970 Declaration on the Principles of International Law.
• Article 2(4) states that all UN Member States must refrain from using or threatening force against the territorial integrity or political independence of any other state, or in any way inconsistent with the Purposes of the United Nations.
• As indicated by the wording of Article 2(4), the use of force is permitted in situations that align with the purposes of the UN. Chapter VII of the UN Charter, titled "Action with Respect to Threats to the Peace, Breaches of the Peace, and Acts of Aggression," outlines the circumstances under which a state can employ military force against other states.
• Force may be employed against another state when:
  • Such action is authorized by the UN Security Council as part of a collective security mechanism.
  • A state is acting in self-defense.
• The threat or use of force is limited to armed force used either directly or indirectly, which can include a state's participation in the use of force by another state or by irregular forces, mercenaries, or rebels. It does not extend to political or economic coercion.
• Article 2(6) of the UN Charter mandates that the UN ensures that non-UN member states act in accordance with the principles of international law to maintain international peace and security.
• The rules laid out in the Charter regarding the use of force are concise and cannot serve as a comprehensive code. Articles 2(4) and 51 primarily address inter-state conflicts, reflecting the context of World War II. However, today, large-scale inter-state conflicts have become less common, and civil wars—with or without state involvement—have become more prevalent. Cross-border guerrilla incursions and limited inter-state skirmishes in border regions have become the norm rather than all-out wars between states.
• The apparently straightforward language of the Charter has led to significant differences of opinion among states. Disagreements have arisen regarding whether the prohibition on the use of force includes economic coercion, the scope of the right to self-defense, the right to use force to promote self-determination outside of the context of decolonization, and the intervention in civil wars. With the United States as a superpower and the end of decolonization, there is a growing call for a reevaluation of international law concerning the use of force.
• Questions have emerged about how far the Charter should be interpreted to permit the use of force to promote democracy, restore order in a state without an effective government, advance the right to self-determination in contexts beyond decolonization, and respond to terrorist attacks. There are also debates about the extent of centralized control by the UN Security Council over these and other uses of force.
• In the Nicaragua case, the International Court of Justice regarded the Charter's provisions as dynamic rather than fixed, implying that they can evolve over time through state practice.

Authorization by the UN Security Council

• The United Nations Security Council has the authority to adopt measures involving the use of force as outlined in Article 42 of Chapter VII of the UN Charter. This represents one of the few situations where the use of force is considered legally justified. However, during much of the Cold War, Article 42 was not put into action because the five permanent members of the Security Council frequently used their veto power to block resolutions that authorized the use of force. As a result, the Security Council was often unable to take effective action in line with its primary responsibility for maintaining international peace and security, as specified in Article 24(1) of the UN Charter.
• The end of the Cold War marked a shift in this dynamic, allowing the Security Council to become more active, and it subsequently adopted a significant number of resolutions.
• Decisions made by the Security Council in accordance with the UN Charter are binding on all Member States, as indicated in Article 25. Article 103 further clarifies that in case of a conflict between a Council resolution and any other international agreements that Member States may have, the Council resolution takes precedence. This means that a Council resolution can require States to act in ways that go against their obligations under other international agreements to which they are party.

Chapter VII of the UN Charter contains provisions concerning:

Action with Respect to Threats to the Peace, Breaches of the Peace and Acts of Aggression. When the Security Council has determined the existence of one of these situations under Article 39, it can decide provisional measures under Article 40.

Pursuant to Article 41, the Council can decide what measures not involving the use of armed force to be applied in order to give effect to its decisions. If such measures under Article 41 prove to be inadequate or the Council consider them to be so, it may take actions involving the use of armed force. Article 42 of the Charter states that the Council may take such action by air, sea or land forces as may be necessary to maintain or restore international peace and security. So far, measures not involving armed force has initially been applied in every situation where force has finally been authorized by the Council.

Article 39- determination provision

• threat to the peace
• breach of the peace
• act of aggression

Threat to the peace

• This is the broadest of the three categories, and it is difficult to find a precise definition. Shaw notes that in a sense it constitutes a safety net for the Security Council where the conditions needed for a breach of the peace or act of aggressions do not appear to be present. Practice since the Kuwait crisis in 1990 has shown that the range of situations the Council has determined to constitute threats to international peace and security has broadened.
• At its most basic, the concept is intended to enable a response to imminent armed conflict between states. Severe intrastate violence (Balkan war prior to splintering of Yugoslavia), serious violations of human rights and humanitarian law (Somalia and other east/central African nations during early 1990s) and terrorism have been designated as threats to peace.
• In Resolutions 1368 and 1373, adopted after the September 11 terrorist attacks in the United States, the Security Council stated that such acts, like any act of international terrorism, constitute a threat to international peace and security.
• The concept includes not only situations in which the use of armed force appears imminent, but where factors subsist that may lead to use of force.

Breach of peace

Breach of peace = hostility between armed units of two states. In SC Resolution 502, the Security Council considered the Argentine invasion of the Falklands to be a breach of the peace even prior to UKs counter offensive. In Resolution 660 the Council determined that the Iraqi invasion of Kuwait was a breach of the peace.

Act of aggression

• In 1974, the General Assembly adopted Resolution 3314 on the definition of aggression.
• Article 1 states that aggression is the use of armed force by a state against the sovereignty, territorial integrity or political independence of another State, or in any other manner inconsistent with the Charter of the United Nations. Furthermore, Article 2 of the resolution says that the first use of armed force by a State in contravention of the Charter shall constitute prima facie evidence of an act of aggression.
• The Council has determined acts of aggression only three times. This was in relation to Israel, South Africaand Southern Rhodesia.
• The inter state use of force in the years since 1991 has not produced anything like the international response triggered by Iraqui invasion of Kuwait. The conflicts which broke out between Ethiopia and Eritrea, Armenia and Azebaijan, Cameroon and Nigeria, Israel and Lebanon, and Ethiopia and Somalia did not provoke the UN to identify an aggressor and to authorize action against it. The reaction of Security Council to the outbreak of inter-state conflict has generally been to avoid condemnation and the attribution of responsibility and rather to call for a ceasefire and the restoration of peace. With regards to Iraq, resolution 678 (1990) authorized member states to use all necessary means to ensure Iraq immediately and unconditionally withdrew all forces from Kuwait and to restore international peace and security in the area.

The Case of Libya

• UN Security Council Resolution 1973 serves as an example of the authorization of the use of force by the UN Security Council. In February 2011, as the Arab Spring began with protests in Egypt and Tunisia, Libyans in Benghazi started peaceful demonstrations against the oppressive regime of Colonel Muammar Gaddafi. They called for his resignation after 42 years of his rule and advocated for a democratic and inclusive Libya. Their demands also included putting an end to the era of oppression and severe human rights violations, such as those that occurred in the Abu Salim prison in 1996. Gaddafi responded to these protests with armed violence against civilian demonstrators, which led to a civil war between the government forces loyal to Gaddafi and the rebel opposition forces.
• On March 17, 2011, the UN Security Council, acting under Chapter VII of the UN Charter, passed Resolution 1973, which authorized member states to take all necessary measures to protect civilians and civilian-populated areas threatened by attacks in the Libyan Arab Jamahiriya, including Benghazi. However, it explicitly excluded the presence of any foreign occupation force on any part of Libyan territory.

Self-Defense and Preemptive Use of Force Against Terrorism

• The traditional definition of the right to self-defense in customary international law originates from the Caroline case. In this historical case, British subjects had seized and destroyed a vessel in an American port because the ship, the Caroline, was supplying American nationals who were conducting raids into Canadian territory.
• The U.S. government argued that the attack on the vessel constituted an attack on American territory. In response, the British government asserted its right to self-defense. The subsequent diplomatic exchanges between the two parties outlined the key elements for legitimate self-defense. Daniel Webster, the U.S. Secretary of State, stressed that, for self-defense to be lawful in international law, certain conditions must be met. These conditions included the necessity of self-defense being instant, overwhelming, leaving no alternative means, and requiring immediate action. The act justified by the necessity of self-defense must be proportionate to that necessity and must be clearly limited by it. These principles were later accepted as customary international law.

Debate Surrounding Article 51 of the UN Charter

• Article 51 of the UN Charter grants the right of self-defense and has sparked extensive debate about the scope of this right. The phrase "nothing in the present Charter shall impair the inherent...self-defense" has been subject to various interpretations. Some writers argue that this provision preserves states' pre-existing rights without explicit provisions, while others contend that the right of self-defense arises only in response to an armed attack and should be narrowly construed. The constraints imposed on self-defense in Article 51 would be meaningless if a broader customary law right to self-defense remained unaffected by these limitations.
• Critics argue that a strict interpretation of Article 51 overlooks the fact that the Cold War and political considerations often paralyzed the Security Council. In practice, states have continued to use force preemptively at times during the UN era, and the international community has continued to assess the legitimacy of these actions based on traditional criteria like necessity and proportionality.
• In practice, states have attempted to use Article 51 to justify the use of force by broadening its scope to include anticipatory self-defense or responses to terrorism.
• In cases like the Oil Platforms case and others, courts have ruled that a state must demonstrate that it has been the victim of an armed attack to justify the use of force in self-defense and that the burden of proof falls on the state. It is essential to establish that the state was intentionally attacked, which was not proven in the case against the US. Determining the threshold for the seriousness of an attack necessary to validate a self-defense response can also be challenging.
• The question of whether Article 51 applies to non-state actors remains contentious. According to the ICJ's definition of aggression in the Nicaragua case, the use of force by individuals constitutes an armed attack only when there has been the sending of armed groups or mercenaries by or on behalf of a state to carry out acts of armed force against another state with such gravity as to amount to acts of aggression. After the 9/11 attacks, the US declared it would not distinguish between terrorists and those who harbored them, treating any nation harboring terrorists as a hostile regime.
• The question of whether the right to anticipatory self-defense has survived the UN Charter is still debated among states and authors. During the Cold War, some argued that self-defense was lawful only if an armed attack had actually occurred. Others, like the United States and the United Kingdom, maintained that force could be used in self-defense in the face of an imminent attack. The International Court of Justice has not addressed this matter, leaving it open. The end of the Cold War and new threats have not led to a consensus among states regarding anticipatory self-defense.
• Defining what constitutes an imminent attack in the context of transnational terrorist groups and weapons of mass destruction remains a challenge. While the Caroline language suggests that self-defense must be immediate and overwhelming, modern circumstances require a broader assessment of imminence. Imminence is determined by the immediacy, nature, gravity of the threat, and the belief that further delay would render the defending state incapable of averting the attack.
• The question of whether international law permits the preemptive use of force without Security Council authorization is unclear. It may be permissible if Article 51 is interpreted expansively to preserve the traditional right of self-defense allowed in customary international law. However, such uses of force must still meet the requirements of necessity and proportionality.
• The difficulty lies in defining situations that meet the necessity test, as it becomes increasingly subjective. There is no consensus, either theoretically or practically, on whether the possession or development of weapons of mass destruction by a rogue state justifies preemptive use of force. While some argue that anticipatory self-defense may be necessary for national survival in cases involving overwhelmingly lethal weaponry, others are hesitant to legitimize preemptive force due to the potential for abuse.

Case Study

Osama Bin Laden Assassination

• On May 2, 2011, Osama Bin Laden was killed during an operation conducted by US special forces, specifically the Navy Seals, in Abbottabad, Pakistan, known as "Operation Neptune Spear." The United States argued that the action to kill Bin Laden was an exercise of its right to national self-defense under Article 51 of the UN Charter. However, it remains unclear whether Pakistan consented to or endorsed the action either before or after the operation. Notably, Pakistan ratified the International Covenant on Civil and Political Rights (ICCPR) on June 23, 2010, which means it cannot consent to violations of international humanitarian law on its territory. US officials publicly stated that they neither sought nor obtained consent from Pakistan.
• If Pakistan did not consent, then prima facie, the actions of the US would be a clear violation of the prohibition of the use of force in Article 2(4) of the UN Charter and a breach of Pakistan's sovereignty. The starting point in international law is that the host state has an obligation to address threats and attacks emanating from non-state actors on its territory. However, there is an argument that a state's right of self-defense can be exercised in another state's territory if that state is unable or unwilling to address the source of the attacks, and the threat continues to pose a significant danger.
• The military action taken would be based on several arguments: (i) Pakistan either knew or should have known about Bin Laden's presence and was unable or unwilling to capture him; (ii) Bin Laden led an organization that had attacked the US, and he continued to pose an imminent threat; and (iii) the use of armed force was necessary and proportionate to address that threat.
• Once a state determines that it has a right to self-defense, it must assess the specific actions it can take in response, including whether the use of force is justified. The standard inquiry involves three elements: whether the use of force is necessary, whether the level of force is proportionate to the initial armed attack or imminent threat, and whether the response is taken at a point close enough to the armed attack (i.e., immediate).

Unwilling or Unable Test

• If there is no consent from the host state (in this case, Pakistan), the unwilling or unable test is applied to determine whether the host state is prepared to suppress the threat. If the host state is either unwilling or unable, it is reasonable for the victim state (in this case, the USA) to consider its own use of force within the territorial state as necessary and lawful, assuming the force used is proportional and timely. If the host state is both willing and able, the use of force would be unlawful.
• The international community generally expects a state using force to follow certain key principles, including asking the territorial state to address the threat, reasonably assessing the territorial state's control and capacity in the region where the threat is emanating, evaluating the territorial state's proposed means to suppress the threat, and considering its own prior interactions with the territorial state.
• Based on the available facts, the US appears to have strong arguments that Pakistan was unwilling or unable to deal with Bin Laden. The US has argued that asking the Government of Pakistan to act against Bin Laden could have jeopardized the mission. The size and location of the compound, along with its proximity to Pakistani military installations, raised doubts about Pakistan's commitment to combating al Qaeda. The US also suspected that certain Pakistani officials might have been aware of Bin Laden's presence and could have tipped him off if they had known about the imminent US action.
• Pakistan might argue that it could have conducted an effective mission itself or that the US should have framed the operation as a joint effort, given their close collaboration in other intelligence and military contexts. However, Pakistan's defense of its sovereignty, while understandable politically, appears weak from an international law perspective.

Balakot Strikes in 2019

• The United Nations Charter allows one state to use force in another state's territory only in self-defense or with the approval of the UN Security Council. In addition to self-defense, the International Law Commission's Articles on Responsibility of States for Internationally Wrongful Acts permit the extraterritorial use of force by a state under certain circumstances, such as with the consent of the other state, out of distress, out of necessity, as a countermeasure, or in response to situations beyond the state's reasonable control (force majeure).
• The use of force in international law often generates debates and lacks consensus among various international stakeholders due to its subjective nature. These debates are especially contentious when the target is non-state armed groups, as was the case in the Balakot Strikes in 2019. However, based on state practice and certain Security Council resolutions, particularly those adopted in response to the 9/11 attacks, the use of force against militant groups in self-defense is increasingly considered an accepted norm.

Operation Bandar

• Operation Bandar, conducted by the Indian Air Force on February 26, 2019, involved 12 Mirage 2000 fighter aircraft attacking a Jaish-e-Mohammed (JeM) terrorist camp in Balakot, Pakistan. This operation was in response to a terrorist attack carried out by JeM on February 14, 2019, in the Pulwama district of Kashmir. JeM, a United Nations-designated terrorist organization, claimed responsibility for the Pulwama attack, which was just one in a series of attacks by the same group against Indian security personnel and civilians in Kashmir and other areas.
• The Indian Air Force's official statement regarding the operation referred to it as a "non-military pre-emptive action," emphasizing that the target was non-state actors, not the military or civilian population of Pakistan. This statement reflected India's position that the airstrikes aimed to destroy JeM's terrorist camps without delving into questions of attribution and Pakistan's state responsibility for the actions of non-state actors operating from its territory.
• India's official statement also cited "imminent danger" as the basis for the pre-emptive strikes, backed by credible intelligence indicating that JeM was planning another terrorist attack. The use of the phrase "pre-emptive strikes" raises questions about whether these actions were anticipatory self-defense (responding to a specific and imminent threat) or preventive self-defense (acting in anticipation of a hypothetical threat, as seen in Japan's attack on Pearl Harbor).
• India argued its case using the "unwilling or unable" test, asserting that Pakistan was unwilling or unable to take action against JeM despite receiving intelligence on the location of JeM terror camps and calls from India to address the threat.
• However, despite the distinction between an attack on a state and an attack on a non-state actor, it does not absolve the attacking state from the UN Charter framework on the use of force. The International Law Association noted that the use of force within another state's territory, even if limited to strikes against a non-state actor, falls within the concept of force as defined in Article 2(4) of the UN Charter.
• India's position that the Balakot aerial strikes were non-military and therefore not subject to the UN Charter's legal framework on the use of force raises questions in the context of international law. While India received support for its right to self-defense following the Pulwama attack and faced no condemnation from other states or the UN after the Balakot airstrikes, further clarification is needed to place this position in a legal context, as it appears unusual from an international law perspective.