The Iran Deal, Explained: What the U.S. Is Actually Demanding and the Legal Problems With It (3 minutes)

By Yusra Suedi (PhD, Assistant Professor of International Law at University of Manchester). This is a developing story and may be updated further.

Mar 27, 2026

The U.S. handed Iran a 15-point ceasefire deal. Iran rejected it and fired back with a counterproposal. Whether they’re actually negotiating is anyone’s guess.

But here’s why the U.S. proposal matters anyway: even a rejected deal is a roadmap. It shows exactly where the U.S. stands, what they’re demanding, and how far things have shifted since the last attempt.

To make sense of it, you need three reference points: (i) Obama’s 2015 JCPOA, which traded sanctions relief for nuclear limits; (ii) Trump’s 2018 demands after he tore it up; and (iii) what the U.S. is asking for now, in 2026, with bombs already falling.

(I’m focusing on the U.S. proposal here as it’s more detailed and reveals more about where talks might go. Iran’s counterproposal essentially says ‘stop bombing us, pay reparations and recognise our sovereignty over Hormuz’.)

So, three questions: how have U.S. demands on Iran evolved since 2015? What are the legal problems with the current proposal? And why does any of that actually matter?

How U.S. Demands on Iran Have Escalated (2015–2026):

(It’s table time… I love tables!)

The arc is stark (rhyme unintentional): 2015 was about constraining Iran. 2018 was about dismantling it. 2026 is about making it defenceless.

© SAIL 2026 - Do not reproduce without permission

(Shoutout to Edge Notes for the tip on presenting this table!)

Four legal problems with the proposal:

A bilateral deal can’t bind the parties that matter most

The JCPOA involved all five permanent UN Security Council members plus the European Union.

The 2026 proposal might become just a bilateral US-Iran deal… let’s see.

But a bilateral deal can’t legally bind the many third parties most affected by the U.S. demands (shipping nations, neighbouring countries, proxy groups).

So if it’s going to be implemented, other countries have to get involved.

Any deal signed under bombardment may be void

Under Article 52 of the Vienna Convention, a deal signed under pressure of military force is legally void.

Iran is still being bombed, which might create pressure for it to agree to something as it wants the aggression to stop.

This hands Iran a legal exit ramp from any deal it signs… and it knows it.

“Unrestricted IAEA access” doesn’t legally exist yet

The IAEA (the UN’s nuclear watchdog)’s inspection runs through specific legal instruments, which define exactly what access means and how it works.

None of them allow “full and unrestricted access”, as written in the 2026 ceasefire deal.

So for this to work, Iran would have to sign new legal agreements or change the existing ones with the IAEA. This will take time.

The U.S. and Iran don’t even agree on what law governs the Strait of Hormuz

The U.S. is demanding Iran promise never to close the Strait of Hormuz… forever. In other words: accept that it’s a transit passage strait, which Iran has little to no control over.

Iran’s counterproposal says the U.S. must recognise its sovereignty over Hormuz. In other words: accept that it’s an innocent passage strait, which Iran has much more control over.

I already covered in my last post that they don’t see eye to eye on what laws govern the Strait, and are both invoking a rulebook neither has signed on to. So it’s unlikely that this point will be resolved.

Why do the legal issues matter here?

Ceasefire deals can sound decisive. But they only last if political demands become workable legal obligations.

When that doesn’t happen because of legal problems, agreements may look strong… then fall apart.

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