Since the end of the Second World War, diplomatic missions around the world have been attacked at least 800 times, according to data compiled by Prof Gabor Kajtar at Eotvos Lorand University in Hungary. Until Israeli jets apparently fired missiles at an Iranian consular building in the <a href="https://www.thenationalnews.com/news/mena/2024/04/02/damascus-residents-stunned-israel-syria-strike/" target="_blank">Syrian</a> capital on Monday, <a href="https://www.thenationalnews.com/news/mena/2024/04/01/syria-damascus-iran-embassy-strike/" target="_blank">killing at least 11 people</a>, none of those attacks were initiated directly and intentionally by a country that was not at war with the one it attacked. As the Belgian law professor Tom Ruys put it in a 2021 paper in the <i>European Journal of International Law</i>: “One could wonder whether there has ultimately been even a single instance where one state intentionally and openly attacked the diplomatic or consular premises of another state in the absence of an ongoing armed conflict between the two.” Embassies are sacrosanct spaces in the world of international relations. The idea of one being targeted in a military air strike was hitherto inconceivable. Why does that matter? With diplomatic missions being attacked so frequently, is it important to distinguish who is doing the attacking, and why? In international law, the answer is yes, and the reason is that those two factors (who and why) determine how the state under attack is entitled to respond. Israel has not yet claimed responsibility for Monday’s air strike, but if it is proven to have carried it out using its own air force, then we may be witnessing, for the first time in modern history, an instance in which a state has committed an act of aggression in this way. And by extension, it would be the first time in modern history that an embassy attack provides a legal justification for a war of self-defence, should Iran take such a step in response. International lawyers – in Tel Aviv, Tehran and elsewhere – will be debating this right now. Military lawyers in Tel Aviv have likely already considered the implications. It is not as though no country has ever tried to invoke a right to military self-defence in response to an attack on its embassy. Since 1945, only one has – the US. And it has done it only five times (a small number, considering America is the victim in about 20 per cent of all attacks on diplomatic missions). But in each of those five instances, the aggressor was a non-state actor – either a terrorist group or an angry mob, meaning no government was held directly responsible. The US responded with military operations or air strikes on facilities it deemed instrumental to the attacks, citing self-defence in its reports to the UN Security Council. And in all five instances, there was no clear consensus – either among UN member states or international courts – that the self-defence justification was valid. Among legal scholars, the question of whether countries can take self-defence measures in another country’s territory in response to the actions of non-state actors is both controversial and murky. Since 9/11 and the US-led “War on Terror”, there has been growing agreement that such actions could be taken, but international law on the subject is far from settled. Where non-state actors have targeted embassies, in all cases but the five raised by the US the affected countries have treated them as diplomatic or criminal matters – not acts of war. What <i>is</i> settled, however, is that self-defence is justified when one state attacks another. In fact, it is the <i>only</i> universally accepted justification for self-defence. In international law, the technical term for an attack that triggers the right to self-defence is an “armed attack”. Amazingly, there is no exhaustive definition as to what exactly constitutes an armed attack, but it is well-established that armed attacks are a subset of the crime of aggression. Consequently, many scholars look to UN General Assembly Resolution 3314 (1974), which defines “aggression”, for examples. Among other things, it includes any attack by the armed forces of one state against the territory or armed forces of another state. Less clear is whether embassies are covered by that definition. Many argue they are not. Contrary to popular belief, embassies are not legally the physical territory of the state they represent. They are, instead, premises with special privileges, considered "inviolable" under international law. Nonetheless, some formidable legal scholars – notably including Christopher Greenwood, a former judge at the International Court of Justice (ICJ) – argue that embassies are “organs of a state” akin to armed forces in this context, and so targeting them would meet the “armed attack” threshold. And as Prof Ruys points out, the fact that attacks on embassies are not explicitly mentioned in Resolution 3314 may itself be “a consequence of the fact that states do not attack other states’ embassies and that the drafters of the Definition of Aggression therefore simply did not contemplate that such a scenario could materialise”. As I mentioned earlier, Iranian government lawyers are no doubt preparing arguments to that effect right now. Whether Tehran chooses to use them to justify a military response against Israel is another matter. We should hope not. Such a response would have devastating consequences in a Middle East that is already beset by violence – including Iran-sponsored violence carried out in several countries via armed proxies. If the Israeli army’s past statements on the subject are any guide, Israeli military lawyers would no doubt have already prepared their own arguments citing that very fact. Most of the people killed in the Iranian mission – and presumably the main targets of Monday’s air strike – were members of Iran’s Islamic Revolutionary Guard Corps, the entity responsible for directing Iranian proxies like Hezbollah in attacks against Israel. Even if Israel resists claiming responsibility for the air strike, its internal logic will have been that the strike itself was an act of self-defence, not aggression. But it is important to say that diplomatic missions are considered civilian targets in the context of war. Even if a person inside is a member of a hostile military, targeting an embassy for the sake of killing that person is almost certainly illegal. If it was indeed behind the attack, as the available evidence suggests, Israel has exposed itself very clearly to charges of aggression, and given Iran the upper hand in meeting the legal threshold for self-defence. Aside from its potential to ignite a war, the air strike in <a href="https://www.thenationalnews.com/news/mena/2024/04/02/who-was-mohammad-reza-zahedi-the-senior-iranian-general-killed-in-damascus/" target="_blank">Damascus</a> may also further drive a wedge between Israel and its closest ally, the US. At the very least, it puts the US in an incredibly awkward position on the international stage. America is the country that perhaps most subscribes to the notion that “an attack on an embassy is considered an attack on the country it represents”. The US State Department has said so, in those exact words, in a section of its website titled “<a href="https://web.archive.org/web/20180510232505/https:/diplomacy.state.gov/discoverdiplomacy/diplomacy101/places/170537.htm" target="_blank">Diplomacy 101</a>”. And again, the US is the only country to have considered such attacks on its premises to meet the threshold for self-defence – most famously (and now ironically) when it argued that point at the ICJ in a legal case about its own embassy being attacked in Iran. In his 2021 paper, Prof Ruys called the hypothetical scenario of one country attacking another’s embassy a “black swan” event – that is, something we’ve never seen before that could invalidate all of our prior assumptions built on past experience. The international community has assumed for decades that embassy attacks don’t launch wars, because up until now they were never serious enough – legally speaking – for the injured state to feel justified in going down that path. But now, the black swan has arrived.