The UN Charter is the founding treaty of the United Nations, signed on 26 June 1945. It binds all 193 member states, prohibits the use of force against other states (Article 2(4)), and preserves the right of self-defence in response to an armed attack (Article 51). The Security Council is authorised under Chapter VII to approve collective use of force.Source: UN

Did the US violate the UN Charter by striking Iran?

Secretary-General Guterres and the governments of Russia and China stated that the US-Israeli strikes violated the Charter. The US disputed this, invoking Article 51 self-defence. No binding Security Council resolution was possible because the US holds a permanent veto.Source: UN Security Council

What is Article 51 of the UN Charter?

Article 51 preserves the inherent right of individual or collective self-defence if an armed attack occurs against a UN member state, until the Security Council has taken measures to maintain peace and security. The US invoked it to justify strikes on Iran; Saudi Arabia, the GCC, and the UAE all invoked it in response to Iranian strikes in 2026.Source: Pentagon

Background

The UN Charter, signed in San Francisco on 26 June 1945, is the founding treaty of the United Nations, binding all 193 member states. Article 2(4) prohibits the threat or use of force against any state's territorial Integrity; Article 51 preserves the right of self-defence in response to an armed attack. Those two provisions are the legal fault line in virtually every interstate conflict since 1945.

Secretary-General António Guterres condemned the US-Israeli strikes on Iran as violations of international law and the Charter at an emergency UNSC session . China characterised the strikes as brazen aggression and a flagrant Charter violation; Russia called them a betrayal of diplomacy. Washington countered that the strikes were lawful under Article 51. The Gulf crisis produced successive Article 51 invocations: Saudi Arabia in April 2026 after Iranian drone strikes on Kuwaiti desalination plants , and the full GCC collectively in the same month. On 19 May 2026, UAE Ambassador Mohamed Abushahab invoked Article 51 self-defence framing at an emergency UNSC session convened after a drone struck the perimeter of the Barakah Nuclear Power Plant — the Arab world's first operational nuclear station — with Russia and China joining the condemnation in the first formal P5 consensus on nuclear-safety language in the conflict.

The Charter's structural weakness is exposed precisely when it is most needed: each of the five permanent Security Council members holds a veto, making enforcement impossible when a P5 state is the accused party. The US is both the depositary state of the Charter and the party accused of violating it — a paradox sharpened by the Pentagon's own legal justifications for the Iran campaign. That contradiction defines the central legal argument about the conflict's lawfulness, and has prompted renewed calls from non-aligned states for veto reform. Cuba invoked the Charter's prohibition on collective punishment at the UNSC in February 2026 in a separate context, illustrating how widely the instrument is deployed across global disputes.

More questions

Why can the UN Charter not be enforced against a permanent Security Council member?

Chapter VII enforcement requires a Security Council resolution. Each of the five permanent members can veto any such resolution. When a P5 state is itself accused of a Charter violation, as the US is in the Iran conflict, the veto makes binding enforcement structurally impossible.Source: UN Security Council

What is the difference between the UN Charter and the Geneva Conventions?

The UN Charter governs when states may use force (jus ad bellum): it prohibits war except in self-defence or with Security Council authority. The Geneva Conventions govern how force is used once fighting begins (jus in bello): rules on prisoners, civilians, and the wounded. Both bodies of law apply simultaneously in the Iran conflict.Source: UN

Source Material

United Nations Charter Statute of the International Court of Justice Charter of the United Nations — Wikipedia UN Charter — Full Text

How the World Sees Them

Iran

Tehran's UN ambassador called the US-Israeli strikes a war crime at the Security Council emergency session, framing Iran's retaliatory actions as lawful Article 51 self-defence. Guterres condemned Iran's retaliatory strikes in the same statement, placing both parties in Charter violation territory.

Global South

Non-aligned states view the conflict as a test case for whether the Charter's use-of-force prohibition applies equally to major powers. The Security Council's structural paralysis reinforces longstanding calls for veto reform before a P5 state is itself a belligerent.

United States

The US drafted key Charter provisions in 1945 and remains its depositary state; Article 51 self-defence is the administration's stated legal basis for strikes on Iran. Washington rejects the characterisation of the campaign as unlawful, asserting Iran's nuclear programme constitutes an ongoing armed threat.

Russia and China

Both states condemned the US-Israeli strikes as flagrant Charter violations at the Security Council. Their joint condemnation extended to the Barakah nuclear-plant strike in May 2026 — the first formal Russia-China consensus on nuclear-safety language in the conflict — while their own P5 vetoes preclude any binding enforcement resolution.