Published: 17 March 2026 Author: Christian Richter
Since the early hours of 28 February 2026, the United States and Israel have been attacking targets in Iran. The air strikes so far have targeted Iranian air defences, missile bases, nuclear facilities and the regime’s top personnel, including its supreme leader Ali Khamenei. Both Israel and the United States justify the attacks on the grounds of threats posed by Iran. The vast majority of commentators have been quick to condemn the military action as a clear violation of international law.
In contrast, Federal Chancellor Friedrich Merz spoke of a dilemma at the beginning of March with regard to the international legal classification of the war in Iran. In his statement on 1 March 2026, Chancellor Merz expressed his solidarity with Israel and the United States and emphasized that Germany would not criticize the attacks on Iran with regard to international law:
The German government is drawing clear conclusions from this for our own actions. Categorizing the events under international law will have relatively little effect. This is especially true when these classifications remain largely inconsequential. Over the years and decades, appeals from Europe, including Germany, condemning Iran’s violations of international law, and even extensive packages of sanctions have had little effect. This is also due to the fact we were not prepared to enforce fundamental interests with military force if necessary. Therefore, this is not the time to lecture our partners and allies.
Upon further inquiry, Chancellor Merz explicitly stated a dilemma as follows:
We have discussed at length within the Federal Government how to classify what is currently happening under international law. We recognise the dilemma that measures and steps under international law – which we have repeatedly attempted to take over the past decades – appear to have no effect whatsoever against a regime that is building up its nuclear arsenal and brutally oppressing its own people. This presents us with a dilemma. But we can at least say this much under international law: it is an ongoing conflict that has persisted for decades, which Israel and the United States of America now wish to end through military strikes, both in view of the terrorism engulfing the entire region and in view of the development of nuclear-capable missiles. There is no ideal time to undertake such an action, but there may come a time when it is too late. That is why our assessment is very comprehensive and leads to the conclusion I have just described to you.
A day later the cabinet spokesperson and head of the Press and Information Office of the Federal Government, State Secretary Stefan Kornelius said:
Yesterday, the Chancellor spoke at length about international law and stated that we are experiencing a dilemma in that Iran’s compliance with international norms has not been established for many years and decades.
This describes the legal situation more accurately. The specific threat situation, the special nature of the right to self-defence and its complex relationship to the prohibition of the use of force and the United Nations Security Council have been largely ignored.
The prohibition of the use of force in Article 2(4) of the UN Charter is deliberately broad and prohibits any use or threat of military force. After two devastating world wars, its purpose is nothing less than to protect world peace. It is one of, if not the central norm of international law, sometimes referred to as the “cornerstone of peace”. On the other hand, Article 51 of the UN Charter confirms that nothing in it shall impair the inherent right of self-defence in the event of an armed attack. In this respect, there is a double asymmetry between the prohibition of violence and the right of self-defence in Article 51 of the UN Charter. On the one hand, the prohibited use of force is broader than armed attack, which is only considered to exist after a certain intensity has been reached. On the other hand, the prohibited threat of military force has no explicit reference point in the wording of Article 51 of the UN Charter.
This imbalance is not problematic in view of the UN Charter’s concept of granting the Security Council the monopoly on the use of force in international relations. In the event of a threat to the peace, a breach of the peace or an act of aggression, Article 39 in conjunction with Article 42 of the UN Charter authorises the Security Council to intervene militarily. However, with very few exceptions, the Security Council is chronically incapable of making decisions and taking action due to regular vetoes by its permanent members. The Security Council is therefore unable to fulfil its central task of securing peace in the world, if necessary by military means. Experience shows that the Security Council does not intervene. States must therefore assume that they are on their own in the event of threats, attacks or aggression and must defend themselves as best they can if they do not belong to a defence alliance. This has been the case for Ukraine for more than four years of Russian aggression. The same applies in principle to Israel. However, in this case, the United States has come to Israel’s aid.
It is almost certain that the Security Council would not have acted due to an expected veto by Russia and China. After all, Iran has been supplying drones for Russia’s war of aggression and conquest in Ukraine for years. In addition, Iran supplies oil to China, which is thus moving closer to its goal of strategic autonomy by making itself more independent from oil suppliers allied with the United States. The foreseeable blockade of the Security Council is particularly regrettable in this case. The Security Council can and should take action in response to threats to peace and, if necessary, take military action.
The paralysis of the Security Council must also be taken into account when answering the question of whether Israel, and thus also the United States, had a right to self-defence in this specific case by way of the right of collective self-defence. The same applies to the fact that the central argument for a purely reactive understanding of the right to self-defence, the seemingly unambiguous wording of Article 51 of the UN Charter, is not so clear-cut. A comparison of the five authentic language versions shows that the right to self-defence is not to be understood as purely reactive. The French version refers to a “cas où un Membre des Nations Unies est l’objet d’une agression armée”, i.e. a case in which a Member State is the object of armed aggression. Accordingly, the majority in international law doctrine and the international community consider self-defence measures immediately prior to an armed attack to be justified in principle.
This understanding is largely based on the customary international law of self-defence, which has its origins in the so-called Webster formula, a statement by US Secretary of State Daniel Webster in the aftermath of the Caroline incident in 1837: “It will be for that Government to show a necessity of self-defence, instant, overwhelming, leaving no choice of means, and no moment of deliberation.” According to this formula, a government must demonstrate a necessity for self-defence that is immediate and overwhelming and allows no choice of means and no moment of deliberation. On the one hand, these criteria are deliberately restrictive, but on the other hand, they also imply that any use of pre-emptive self-defence must be assessed on a case-by-case basis. This leaves room for consideration of the special nature of the right to self-defence.
Secretary of State Webster speaks of the “great law of self-defence”. According to Hugo Grotius, who was cited by Secretary Webster, the right of defence arises from what nature recommends to everyone. The right to self-defence is one of the fundamental principles of international law, probably best described as a right of its own kind. The wording of Article 51 of the UN Charter also leaves room for this interpretation, referring to a natural right in both the French and Chinese versions. The essence of the right to self-defence is that no legal system has the authority to demand the self-sacrifice of one of its subjects. In view of this, the previous requirement of an imminent attack must be carefully supplemented in individual cases. The special nature of the threat posed by terrorist regimes and weapons of mass destruction must be taken into account.
The Iranian government has enriched uranium to over 60 per cent in various deep bunkers. From a technical point of view, enrichment to weapons-grade 90 per cent uranium would therefore have taken only a few weeks. The allegedly purely peaceful use of nuclear energy requires only about 5 per cent uranium enrichment and is therefore a myth. With the massive attacks by its proxies – Hamas, Hezbollah and the Houthis – in recent years, Tehran has also followed up on its decades-long regular announcements of destruction against Israel with action. Only the presumably overly narrow standard of the International Court of Justice prevents these attacks by the Islamic Republic of Iran from being classified as armed attacks under international law, which could lead to Israel’s reactive right to self-defence. In any case, the attacks are a manifestation of the constant threats, which must therefore be taken seriously. Ultimately, the Iranian regime has the necessary ballistic missiles, which Israel cannot completely intercept in a concerted attack, as was already the case with Iran’s attacks in 2024 and 2025. Added to this is Israel’s lack of strategic depth. A single nuclear missile could potentially lead to the destruction of the State. This behaviour, which violates international law, is attributable without exception to the Islamic Republic of Iran and is solely its responsibility. Accordingly, it is only logical to include this in the threat analysis of an imminent armed attack.
Therefore, the Israeli and US air strikes do not constitute aggression. If anything, they should be described as a breach of the peace. Contrary to isolated voices, the West is therefore not applying double standards. Russian aggression is categorically different, as already shown by Article 39 of the UN Charter, which distinguishes between a breach of the peace and aggression.
The attacks on Iran involve a conflict of objectives between two fundamental principles of international law: the prohibition of the use of force and the right to self-defence. This conflict cannot be satisfactorily resolved by merely pointing to the rule-exception relationship between the prohibition of the use of force and the right to self-defence, or by an overly rigid understanding of the conditions for the right to self-defence. This would mean that international law requires a State to passively endure its own impending demise. Since international law is not only to be obeyed by States, but also created by them, this is not plausible. The right to self-defence is the last right that sovereign States would renounce. The result is a dilemma under international law that does not rule out the possibility that the attacks were covered by the right to self-defence.
Category: Use of Force
DOI: 10.17176/20260318-145817-0
