🌊 The Red Line in Iran Negotiations

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By Max Frost

“Enrichment is absolutely nonnegotiable.” 

So said Iran’s foreign minister last week. 

Then came Ayatollah Khamenei, Iran’s supreme leader: Talking about enrichment was “nonsense,” the US “should not try to talk” about it, and doing so would be a “big mistake.” 

But the Americans are talking about it. 

“We have one very, very clear red line, and that is enrichment. We cannot allow even 1% of an enrichment capability,” said Trump’s chief negotiator, Steve Witkoff. 

White House press secretary Karoline Leavitt then reinforced the point: “We are 100% committed to that red line.”

Whether US-Iran negotiations succeed or fail, and whether Israel bombs Iran’s nuclear facilities, may ride on the word “enrichment.” But what even is it?

In March, President Trump wrote a personal letter to Iran’s Supreme Leader Ali Khamenei. 

While Trump had unilaterally withdrawn the US from the Obama-era “Iran Deal” (the JCPOA), he now wanted to secure a lasting peace with Iran. Trump had US envoy Steve Witkoff hand deliver the letter through the United Arab Emirates, along with a two-month deadline to broker a new nuclear agreement. 

Iran initially brushed it off, calling the outreach performative. But by the end of March, Tehran signaled a readiness to engage, albeit indirectly.

On April 12, 2025, the sides met in Oman, a neutral Middle East country, for the first time since the collapse of the JCPOA in 2018. 

The talks began with cautious, indirect conversations. Witkoff and Iranian Foreign Minister Abbas Araghchi never sat in the same room. Instead, messages were relayed through Omani intermediaries – diplomacy by proxy, a reminder of how deep the mistrust still runs.

Since that first encounter, the two sides have met multiple times in both Oman and Rome. The fifth round wrapped up on May 23, 2025, again in Rome. Officials on both sides have hinted at progress, however, core disagreements remain. Chief among them: Iran’s uranium enrichment.

That phrase – uranium enrichment – has become the central sticking point in nearly every negotiation between Iran and the West. 

Uranium, in its natural form, isn’t very useful for nuclear energy or weapons. Nearly 99.3% of it is uranium-238, which is not fissile. Only about 0.7% is uranium-235 – the isotope that can sustain a nuclear chain reaction. To make it usable, the uranium must be enriched, or concentrated, to increase the percentage of U-235.

Editor’s Note

Nothing like starting your Monday with some uranium enrichment! 

We hope you all had a nice weekend. Curious to hear your thoughts on a potential nuclear deal: Good idea? At what cost? Will Trump be able to pull off a tighter agreement than Obama did? Let us know by replying to this email.

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–Max and Max