Against a backdrop of mounting regional instability, political and military developments in the MENA are now inseparable from the legal considerations surrounding them.
Indeed, when sovereign states face a large-scale armed attack, they have a legal right to self-defence. This is particularly relevant in the case of Iran’s ongoing attacks on Gulf Cooperation Council states (GCC) and Jordan, which, following the US-Israeli aggression against Iran since late last month, take on significance beyond their immediate military dimension.
These events have sparked an important legal debate over the legitimacy of seeking external military support, the limits of such assistance, and the international legal frameworks governing it.
The inherent right to self-defence
Last month, Iran launched a coordinated attack using ballistic missiles, cruise missiles and armed drones against all six GCC states, in addition to Jordan, in what Tehran described as a response to joint US-Israeli strikes targeting Iranian territory.
These attacks resulted in the deaths of at least nine people, injuries to more than 200 others, and extensive damage to civilian infrastructure across the Arabian Peninsula.
What distinguishes this incident from previous episodes of regional tension is not only its scale, but also its legal nature. Because Iran launched attacks on sovereign states that had explicitly declared neutrality and actively sought to facilitate diplomatic channels to avoid confrontation.
Article 51 of the United Nations Charter affirms what it describes as the “inherent right” of individual and collective self-defence if an armed attack occurs against a member state until the Security Council takes measures necessary to maintain international peace and security.
This carries particular doctrinal weight. It indicates that this right predates the Charter as a rule of customary international law rather than merely being treaty-based.
Collective self-defence, as an extension of this right, therefore allows a third state to intervene militarily in support of a state subjected to an armed attack, provided a set of defined conditions is met.
The most authoritative judicial clarification of these conditions was set out in the 1986 International Court of Justice (ICJ) judgement in the case concerning Military and Paramilitary Activities in and against Nicaragua. The court established strict and sequential requirements forming the operational threshold for invoking collective self-defence.
The court required the occurrence of an armed attack of sufficient gravity. And it distinguished between “the most grave forms of the use of force” and less severe uses, such as the provision of weapons or logistical support.
Furthermore, the victim state must declare that it has been subjected to an armed attack, and must formally request military assistance from the intervening state or states. Any response must also satisfy the conditions of necessity and proportionality.
Finally, the Security Council must be notified.
Although the Nicaraguan framework has faced academic criticism for, in some scholars’ view, imposing excessive formal constraints on an inherent right, it remains the authoritative judicial standard. It also continues to directly shape the legal analysis of contemporary conflicts.
Meeting the conditions
The Iranian strikes carried out in February and March very clearly meet the conditions set out by the ICJ.
In terms of the threshold of an armed attack, these strikes constituted a grave use of force. They involved the simultaneous launch of hundreds of ballistic and cruise missiles and more than 1,000 drones against sovereign states. They targeted airports, seaports, oil facilities, residential areas, hotels and diplomatic missions, which amounts to a grave armed attack.
This did not involve an ambiguous or indirect use of force, border skirmishes, or covert arms transfers of the type the ICJ distinguished in the Nicaragua case.
The United Arab Emirates alone, by 4 March, had been targeted by 189 ballistic missiles, 941 drone attacks and three cruise missiles.
A joint statement by the GCC and the European Union condemning the strikes as “indiscriminate” affirmed that they were not limited to legitimate military targets. The GCC ministerial council also convened in an extraordinary session, condemning the attacks as a serious violation of state sovereignty and a clear breach of international law and the UN Charter.
In an emergency Security Council session, the Bahraini ambassador, speaking on behalf of the GCC member states, Syria, and Jordan, held the Iranian government fully responsible. This was followed by separate national statements in which affected states confirmed the attacks on their territories.
Saudi Arabia stated it had been targeted and would take necessary measures to defend itself, and Qatar confirmed casualties and said it had intercepted Iranian aircraft.
Crucially, the GCC ministerial council explicitly affirmed the member states’ legal right to individually and collectively respond under Article 51.
Additionally, the joint GCC-EU statement also clearly affirmed the inherent right of GCC states to self-defence under this provision.
The Security Council was notified on the same day the attacks began and an emergency session was convened at the request of Bahrain, France, Russia, China and Colombia. The secretary-general addressed the council, calling for restraint. GCC states presented their position to the assembled members.
Regarding the requirements of necessity and proportionality, the continuation of Iranian attacks, albeit intermittent until at least 6 March, reinforces the conclusion that the threat remains ongoing. It has not ceased.
GCC states repeatedly affirmed their preference for dialogue and diplomacy. At the same time, they maintained their right to take all necessary measures to defend their security.
Sovereignty
In addition to the UN Charter, the GCC possesses a treaty-based collective defence mechanism structurally similar to Article 5 of the North Atlantic Treaty Organisation. Article 2 of the GCC Joint Defence Agreement provides that any attack on one member state is considered an attack on all, and any threat to one is a threat to all.
Article 3 operationalises this principle. It obliges member states to act immediately to assist any member state subjected to aggression, including by using military force. In this sense, the agreement also embodies the collective commitment under Article 51 of the Charter. It integrates the regional framework into the broader international legal order.
This agreement was already activated in an unprecedented manner in September 2025 following an Israeli strike on Doha. The GCC declared the principle of indivisible security among its members. The recent Iranian attacks further reinforced and significantly expanded this activation.
Since the ministerial council reaffirmed full solidarity and a unified position, and stressed that the security of any member state is inseparable from that of all member states, joint air defence systems have been operated. Reconnaissance and security coordination have also been intensified.
While the agreement primarily regulates mutual obligations among GCC members, its explicit grounding in Article 51 also provides a clear legal framework for requesting and coordinating external assistance.
A third independent legal basis is the principle of intervention by invitation. This is a well-established rule of customary international law that allows a legitimate government to consent to the presence of foreign forces and to their conduct of military operations on its territory. It rests on the concept of sovereignty itself.
Force used with the consent of the territorial state does not, in principle, fall within the prohibition set out in Article 2(4) of the Charter since it does not target the territorial integrity or political independence of that state.
The ICJ addressed this principle in both the Nicaragua case and the Armed Activities on the Territory of the Congo case in 2005. It affirmed that a valid invitation must come from a legitimate government exercising effective control, not from non-state actors or insurgent groups.
All six GCC member states are internationally recognised sovereign governments exercising effective control over their territories. Accordingly, any invitation they extend to external partners constitutes a lawful basis for foreign military presence and related operations.
The legal foundation for GCC states in requesting and receiving military assistance rests on three complementary and mutually reinforcing frameworks. Article 51 provides the primary basis for the right of collective self-defence, with the conditions articulated by the ICJ.
The GCC Joint Defence Agreement establishes a regional treaty-based obligation, inspired by the NATO collective security model, which has been activated and reaffirmed during the current crisis.
The customary law principle of intervention by invitation authorises each GCC state, as a legitimate sovereign government, to consent to foreign military presence and operations on its territory.
Again, what lends this legal framework particular force is the unprecedented nature of the Iran attacks. They amount to a simultaneous assault on six states that sought neutrality and pursued diplomacy. Therefore, the convergence of these frameworks provides a structured and regulated legal pathway for action.
Of course, this only applies if GCC states and their partners determine that military assistance has become necessary to restore security and deter further aggression.
The question of whether states subjected to Iranian attacks may request military assistance is neither a purely political choice nor an exceptional measure lacking legal basis. It is grounded in public international law, regional Gulf commitments, and the principle of sovereignty itself.
The scale, scope, and simultaneity of Iran’s attacks have presented Gulf states with both a security challenge and a legal test. In this context, collective self-defence, regional collective defence, and intervention by invitation all intersect. They form a coherent and interlocking foundation.
In this sense, requesting assistance is not an exceptional expansion of force but a regulated legal response to a clear armed attack that meets the conditions of international law.
