22MAR

UK attorney general: war unlawful

3 min read

05:50UTC

The UK attorney general advised that the US-Israeli campaign breaches international law. Starmer opened British bases for it anyway.

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ConflictDeveloping

Key takeaway

Unlike Iraq 2003, the UK government has acted against — not around — its chief legal officer's formal advice.

Lord Hermer KC, the UK attorney general, advised the government that the US-Israeli military campaign against Iran does not accord with international law ¹. That assessment shaped Prime Minister Starmer's initial refusal on 28 February to grant Washington access to any British military facilities ². Starmer reversed within 48 hours, authorising "specific and limited defensive operations" from RAF Fairford and Diego Garcia while refusing RAF Akrotiri in Cyprus for offensive strikes. A former Director of Public Prosecutions now facilitates operations his own chief law officer assessed as unlawful.

Chatham House published analysis arguing the distinction between defensive and offensive base use "blur[s] the line between lawful self-defence and unlawful war on Iran" ³. Under Article 16 of the International Law Commission's Articles on State Responsibility, a state that knowingly aids another's internationally wrongful act bears international responsibility — regardless of how it categorises its contribution. The label "defensive" does not insulate London if the underlying campaign is assessed as unlawful.

The UK faced a version of this in 2003. Attorney General Lord Goldsmith's advice on the Iraq invasion — initially equivocal, later firmed up under political pressure — consumed the Chilcot Inquiry for seven years and destroyed the Blair government's credibility on the use of force. Starmer's legal exposure is sharper: Goldsmith's advice was ambiguous; Hermer's, as reported by Middle East Eye, is not ⁴.

Iran had warned the UK on Thursday that permitting US access to British bases made Britain "a participant in aggression." Within hours of London confirming that access, two intermediate-range ballistic missiles were fired at Diego Garcia — the first Iranian weapons aimed at British sovereign territory in this conflict. One malfunctioned; the other was intercepted; no damage resulted. Britain is now the only European state absorbing direct Iranian retaliatory fire, while the Coalition of Hormuz-statement signatories has grown from seven to 22 without a single warship deployment.

Deep Analysis

In plain English

Every British government has a lawyer called the Attorney General who advises whether government actions are legal under international law. In 2003, the Attorney General eventually said the Iraq War was legal — so the government proceeded, and controversy centred on whether that advice was genuinely independent. This time, the Attorney General has said the operation does not accord with international law. The difference is that the government gave the US base access anyway, without the legal advice changing. This matters because it establishes a precedent that the government can act contrary to its own published legal opinion when alliance politics demand it — and because it creates a documentary record that future courts, inquiries, or parliamentary committees will find easier to work with than the contested advice trail from 2003.

Deep Analysis

Synthesis

Hermer's advice creates an evidentiary record that distinguishes the current UK position from every prior military intervention in living memory: the government acted with documented legal warning rather than despite legal uncertainty. This shifts future accountability from 'the government was misled about legality' — the Iraq template — to 'the government was told and proceeded anyway.' The Chatham House critique compounds this by arguing the defensive/offensive distinction is not merely contested but legally incoherent, potentially exposing specific ministers and officers to individual accountability under the ILC Articles on State Responsibility.

Root Causes

The structural cause is the absence of a UK War Powers Act. Unlike the US, where Congress holds constitutional declaration authority, British prime ministers can commit military assets through royal prerogative without parliamentary authorisation. This concentrates legal risk in the executive with no distributional accountability mechanism — meaning the legal advice was the only institutional check available, and it has been overridden without formal procedure.

What could happen next?

Risk
ICJ or ICC proceedings against UK government officials for complicity in unlawful use of force are procedurally easier given the documented, unrevised contrary legal advice.
Long term · Suggested
Precedent
A sitting attorney general's published international law advice overridden by executive action weakens the constitutional norm that legal advice constrains royal prerogative in military matters.
Long term · Assessed
Consequence
Parliamentary opposition holds a clear legal hook for judicial review of the basing decision, given the existence of undisputed contrary attorney general advice.
Immediate · Assessed
Risk
US allies facing analogous basing pressure — Australia, Canada, Japan — may read the UK precedent as licence to override domestic legal advice under alliance pressure.
Short term · Suggested

Source Landscape

This story draws on centre-left-leaning sources from United Kingdom

United Kingdom×3

Primary parallel: Attorney General Lord Goldsmith's evolving Iraq advice (2003) is the direct precedent — he initially advised war was unlawful, then issued a revised opinion finding it legal under existing UNSC resolutions, giving Blair political cover. The critical distinction: Hermer has not revised his advice. The government has acted contrary to it.

Counter-parallel: The Kosovo intervention (1999) proceeded without UNSC authorisation and without a UK attorney general declaring it unlawful — the 'illegal but legitimate' framing provided political cover that is unavailable here because no comparable humanitarian justification has been formally advanced for the current operation.

Why it’s relevant now

The Iraq precedent ultimately produced the Chilcot Inquiry (2016) and lasting damage to Blair's legacy. Hermer's unrevised advice creates a cleaner evidentiary record for any future public inquiry and a more direct path to individual ministerial accountability than Goldsmith's eventual endorsement allowed.

Consensus view: Philippe Sands KC (UCL Faculty of Laws) and the Chatham House International Law Programme have argued that material support — including basing — to a Coalition conducting strikes on sovereign territory triggers co-belligerent status under Articles 16–18 of the ILC Articles on State Responsibility, regardless of 'defensive only' framing.

Counter-view: The American Society of International Law (ASIL) and US State Department legal advisers have historically maintained that base access for logistical and defensive purposes does not constitute armed attack participation under IHL — a position that Gulf Cooperation Council legal frameworks, anchored in Bahrain, have generally accepted and which provides the legal architecture for continued US-UK operational coordination.

Key tension: The ICJ has not ruled definitively on whether base access alone triggers co-belligerent status under IHL; this remains a genuinely contested doctrinal question rather than settled law, which is precisely why Hermer's advice is politically explosive but legally inconclusive.

First Reported In

Update #44 · Trump: 48 hours to destroy Iran power grid

Chatham House· 22 Mar 2026

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Causes and effects

This Event

UK attorney general: war unlawful

The UK government's chief legal adviser assessed the US-Israeli operation as contrary to international law — advice Starmer overrode within 48 hours. The gap between legal counsel and political action parallels the Iraq War's Goldsmith controversy, while Iran's retaliatory strike on Diego Garcia within hours of the base authorisation made the consequences operational.

Led to

Corbyn bill demands vote before base use

Attorney General's advice that operations do not accord with international law strengthened the case for parliamentary oversight legislation.

Occurred 22 Mar 2026

Read story →

Different Perspectives

IAEA

Director General Rafael Grossi appeared in person at the UNSC on 19 May and warned that a direct hit on an operating reactor 'could result in very high release of radioactivity'. The session produced a condemnation record but no resolution, and the Barakah perimeter was already struck on 17 May.

Hengaw (Kurdish rights monitor)

Hengaw documented three judicial executions and the detention of Kurdish writer Majid Karimi in Tehran on 19 May, establishing Khorasan Razavi province as the newest geography in Iran's wartime judicial record. The organisation's Norway-based operation continues to surface a domestic repression track running in parallel with every diplomatic and military development.

India

Six India-flagged vessels conducted a coordinated cluster transit under PGSA bilateral assurances during the 17 May window, paying no yuan tolls. New Delhi's inclusion in Iran's state-to-state passage track insulates Indian energy supply without requiring endorsement of the PGSA's yuan-toll architecture or alignment with the US coalition.

Pakistan

Pakistan is the only functioning diplomatic bridge between Tehran and Washington. Its role is relay, not mediation in the settlement sense: it conveyed Iran's 10-point counter-MOU in early May, relayed the US rejection, and is now passing 'corrective points' in the third documented exchange of this sub-cycle without either side working from a shared text.

UK and France (Northwood coalition)

Twenty-six coalition members have published no rules of engagement eight days after the Bahrain joint statement; Lloyd's underwriters have conditioned war-risk reopening on written ROE from either Iran or the coalition. Italian and French mine-countermeasures deployments are operating on the in-water clearance task CENTCOM Admiral Brad Cooper's 90% mine-stockpile claim does not address.

Saudi Arabia

Riyadh has not publicly commented on the Barakah strike or the 50-47 discharge vote. Saudi output feeds the IEA's $106 base case; the $5 Brent premium above that model reflects institutional uncertainty no Gulf producer can compress through supply adjustment alone.