There is a war on between the United States and Iran, and the terms on which it ends turn out to involve a fairly unusual sales pitch. Mike Waltz, the US ambassador to the United Nations, went on NBC’s Meet the Press on Sunday and volunteered that, in earlier negotiations aimed at ending the war, American negotiators tried something creative: they offered to sell Iran uranium.

“Heck, our negotiators even offered to sell them uranium,” Waltz said. The idea was a civilian nuclear programme in which Washington supplies the fuel, an arrangement he compared to the one the United Arab Emirates has — “a peaceful programme, right there in their neighbourhood, and they abide by international law and inspection regimes.”

The mechanism here is worth spelling out, because it is the entire nonproliferation argument in miniature. The thing that worries everyone about Iran’s nuclear programme is not the reactor; it is the centrifuges. If a country enriches its own uranium, the same machines that make reactor fuel can, with adjustments, make something else. If a country buys its fuel from abroad, it never needs the machines, and outsiders can count what goes in and comes out. The UAE deal is the model: a nuclear programme with the enrichment bit amputated. Offering to sell Iran uranium — to be its fuel supplier — is a way of saying: you can have the nuclear programme, just not the part of the nuclear programme we actually care about.

Iran, according to Waltz, said no. You can construct arguments for why: domestic enrichment has been a point of national sovereignty in Tehran for decades, and there is an obvious awkwardness in becoming dependent on fuel deliveries from the country currently at war with you. A customer relationship requires a certain baseline of trust, and the baseline here is low. But Waltz’s point in going public with the offer was simpler — to establish, for the record, that Washington offered the peaceful route and Tehran declined it.

Meanwhile, the more immediate item on the table is the Strait of Hormuz. Iran put forward a proposal to end the war and reopen the waterway — it had previously floated a plan to open it within seven days — and on Saturday Donald Trump gave his answer. “I reject their proposal,” he told reporters, adding that Iran wants an agreement because it is “losing so badly.”

The reasoning, as experts described it to Al Jazeera, is that sanctions pressure is a ratchet: the longer Iran stays shut out of its own shipping lane, the worse its position gets, and the more it will concede later. Trump, on this view, believes Washington gains more by waiting than by signing now. The same experts noted the obvious hazard in that logic — wait too long and the leverage erodes rather than compounds, as the costs of a closed strait spread.

A few hours after the rejection, explosions were heard in the strait, according to Iranian media. Reports of blasts near Qeshm Island, off Iran’s southern coast, suggested that multiple antiship missiles and drones were fired at vessels transiting the waterway against Tehran’s wishes.

So the present state of play: Iran proposes to reopen the strait, the US says Iran is losing too badly to be negotiated with, and somebody fires missiles at the ships anyway. It is worth sitting with the uranium detail for a moment. In most contexts, an American admission that “our negotiators even offered to sell them uranium” would be the scandal. Here it is the peace offering, and the scandal is that it wasn’t accepted.