Andrew Stevenson

The British Prime Minister is to be commended for his reaction to the latest violent breach of international law by the US and Israel. He told the Commons: “The lessons of history have taught us that it is important… that we establish that there is a lawful basis for what the United Kingdom is doing. That is one of the lessons from Iraq.”

The United Nations Organisation 1945 Charter states (Principle 4 of Article 2): “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state”

This is subject to Chapter VII, which includes Article 42. This empowers the organisation’s Security Council to “take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security.” Also in that Chapter, Article 51 permits the exercise of “the inherent right of individual or collective self-defence if an armed attack occurs against a Member of the United Nations, until the Security Council has taken measures necessary to maintain international peace and security.”

In 1990, Chapter VII was the basis for Security Council Resolutions 660 and 678, calling for Iraq to leave Kuwait and, after it failed to do so, authorising Member States to expel it by force. This was the legal foundation for the Gulf War. By contrast, the invasion of Iraq in 2003 was neither in self-defence against armed attack nor sanctioned by a Security Council resolution authorising the use of force. The UK should never have participated.

There is nothing explicit in Article 51 to permit pre-emptive action. The wording clearly requires an “armed attack” before self-defence is allowed. Russia’s invasion of Ukraine in 2022 entitles the latter to defend itself, having been the subject of such an assault.

Article 51 does not appear to encompass what is sometimes referred to as “anticipatory self-defence”. This concept was considered in 1837 during the Upper Canadian Rebellion, when Canadian militiamen crossed the US border and attacked American steamboat Caroline, setting it on fire, then sending it over Niagara Falls. In the aftermath of this spectacle, politicians devised the “Caroline Doctrine” whereby pre-emptive strikes violating territorial integrity would be justified only exceptionally, where the necessity of that self-defence is “instant, overwhelming, and leaving no choice of means and no moment for deliberation”. (Very) arguably, the use of “inherent” in Article 51 leaves implicitly open the Caroline Doctrine. Otherwise a country would have to wait until it is attacked before it could retaliate in self-defence, even if foreign troops had been massing ominously on its borders. Neither the UN Charter nor the doctrine allows stronger states to abduct or murder individuals in weaker countries, even those who are hostile and violate the human rights of their own populace.

The 2026 armed attacks on Iran are certainly not the subject of any Security Council resolution authorising the use of force. In addition, since Israel and the USA bombed first, they were not deploying self-defence following an attack. As with Iraq, there is no evidence the Caroline test is met. Iran, on the other hand, is given the right of self-defence under Article 51, at least until the Security Council takes measures to maintain peace and security. Sir Keir was right to maintain that the UK needs to act in accordance with international law. Without an effective UN, the world is a more dangerous place for everyone.

Andrew Stevenson is secretary of Scottish Law Agents Society. This article first appeared in The Scotsman.