2026 Iran Conflict: Legality of Strikes and Escalating Tensions

The coordinated attacks launched by Israel and the United States on Iran on February 28, 2026, have ignited a new phase of conflict in the Middle East. While the UK did not participate in the initial strikes, it has since stated its willingness to engage in “defensive action.” This escalation raises critical questions about the legality of these actions under international law, particularly in light of the 2003 Iraq invasion and the ongoing Middle Eastern crisis that began in 2023 [1].

Were the Initial US and Israeli Strikes Lawful?

Legal experts are largely in agreement that the initial strikes by the US and Israel were unlawful. Israeli President Isaac Herzog argued that Iran’s alleged pursuit of a nuclear weapon justified the attacks [3]. However, Article 51 of the UN Charter recognizes the inherent right of individual or collective self-defense if an armed attack occurs. A broader interpretation allows for the use of force in response to an “imminent threat,” but this remains a contentious point in international law.

Susan Breau, a professor of international law, notes the controversy surrounding the “imminent threat” doctrine, stating that academics are divided on its meaning. She argues that, in this case, there appears to be no evidence of an imminent threat posed by Iran [3]. Previous statements, such as former President Trump’s claim of having “obliterated” Iran’s nuclear program, contradict the assertion of an immediate danger.

Victor Kattan, an assistant professor of public international law, emphasizes that “having blood-curdling rhetoric or threatening violence in and of itself does not give a state the right to use pre-emptive force” [3].

Is the UK’s Defensive Operation Lawful?

The legality of the UK’s position, which involves intercepting drones and missiles targeting regional allies and providing limited defensive action against missile facilities in Iran, is less clear. The UK has stated it is acting in the collective self-defense of allies who have requested support, citing Article 51 [3]. Article 51 requires a request from the victim of an attack for intervention.

However, the UK’s reliance on a US request is a point of concern for legal experts. Philippe Sands, a professor of law, explains that the UK can defend itself if its base in Cyprus is attacked, but providing defensive support for an unlawful attack – such as the US and Israel’s strikes on Iran – is “far more problematic” [3].

Is Iran’s Response a Breach of International Law?

Iran is entitled to respond to the attacks by the US and Israel by targeting military bases, invoking its right to self-defense. Iranian Foreign Minister Abbas Araghchi has stated that Iran is acting in self-defense [1]. However, reports of attacks on civilian targets, such as a hotel and airport in Dubai, and accusations of “indiscriminate” attacks against non-involved countries raise concerns. Deliberate attacks on civilians are illegal under international humanitarian law, and attacks on countries not participating in the conflict are also prohibited.

Escalation and Regional Impact

As of March 2, 2026, the conflict continues to escalate. Hezbollah has joined the conflict [1]. The Strait of Hormuz has been closed by Iranian forces [1], and hundreds of thousands of travelers are stranded in Gulf states due to airspace closures and flight cancellations [2]. The US State Department has urged Americans to depart numerous Middle Eastern countries [2].