Five Reasons the US-Iran Ceasefire Is Legally Fragile (in 3 minutes)
By Yusra Suedi (PhD, Assistant Professor of International Law at University of Manchester)
Trump announced he would pause bombing Iran for two weeks and Iran said it would open the Strait of Hormuz.
Both are gearing up for negotiations mediated by Pakistan.
But literally hours after the announcements, Israel bombed Lebanon and Iran started blocking Hormuz traffic again.
What’s going on? Beyond the obvious geopolitical tensions, this ceasefire is also legally fragile. Here’s how:
1. The U.S./Iran haven’t committed to identical terms
The US and Iran have both publicly committed to something: a two-week pause, stopping attacks, opening the Strait of Hormuz.
But they haven’t committed to identical terms.
Compare what they actually said:
On the Strait of Hormuz, Trump said “COMPLETE, IMMEDIATE, and SAFE OPENING” while Iran said “safe passage via coordination with Iran’s Armed Forces and with due consideration of technical limitations”. Those are two different things.
So if Iran blocks ships citing ‘technical limitations’ and the US calls it a breach, it’ll be hard to settle who’s right.
2. The ceasefire isn’t a binding treaty
The ceasefire would be binding if it were a treaty: a written agreement between states.
Instead: separate social media posts saying different things.
3. U.S./Iran haven’t made binding unilateral statements either
Fun international law fact: a country can legally bind itself just by publicly saying it will do something, as long as it intends to be bound by that statement.
But these social media posts are phrased conditionally: “I will do X if you do Y (my action depends on you)”:
The U.S.: “subject to the Islamic Republic of Iran agreeing to the COMPLETE, IMMEDIATE, and SAFE OPENING of the Strait of Hormuz”
Iran: “If attacks against Iran are halted, our Powerful Armed Forces will cease”
A unilateral declaration is ‘I will do X’ unconditionally.
Conditioning on the other side’s performance shows you don’t intend to be legally bound no matter what. These are political commitments, not legal obligations.
So if either side breaks its “promise,” no one can credibly say “you violated international law” because neither side actually accepted a binding legal obligation.
4. It hasn’t defined what’s allowed in the next two weeks
Can the US resupply its military bases in Qatar?
Can Iran repair bombed power plants and weapons facilities?
Can either side move troops or bring in fresh weapons systems?
Can Israel continue its invasion of southern Lebanon?
Nobody knows, because the parties never agreed on these points.
The result is a pause that exists only as long as neither side decides to start bombing again, making the ceasefire inherently unstable.
5. There’s no ‘referee’
There’s no mechanism to determine when it’s been violated or who violated it first.
No arbitration panel. No monitoring body. No enforcement mechanism.
That means either side can claim the other broke the deal, restart hostilities, and face no consequences…
Ceasefires rely entirely on both sides’ good faith. And I suspect that’ll be in short supply after weeks of bombing each other...
Conclusion
This ‘ceasefire’ is held together by political convenience, not legal obligation. And that makes it extremely fragile.
Next: the Islamabad talks, where the US and Iranian proposals need to be hammered into a single, binding agreement.
Let’s hope for the best.
Stay tuned for more legal breakdowns right here on SAIL.
Other SAIL posts you might enjoy:
Israel’s Occupation of Southern Lebanon: A 3-Minute International Law Breakdown
The US-Israel-Iran War Has Been Ugly. Here’s What International Law Says (in 3 minutes)
The Strait of Hormuz: A 3-Minute International Law Breakdown
10 Days, 10 Issues: The International Law of the US-Israel-Iran War (in 3 minutes)
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