Kazakhstan just raised its hand for one of the most sensitive jobs in global nuclear diplomacy: taking custody of Iran’s enriched uranium stockpile.

President Kassym-Jomart Tokayev publicly offered on May 11 to assist in resolving the Iranian nuclear issue, contingent on the US and Iran actually reaching a deal.

Why Kazakhstan, and why now

Kazakhstan produces roughly 38.6% of the world’s uranium, making it the single largest supplier on the planet with annual output of around 23,270 tons. It also hosts the International Atomic Energy Agency’s Low Enriched Uranium fuel bank at the Ulba Metallurgical Plant, the only facility of its kind anywhere in the world.

Iran currently holds approximately 440 kg of uranium enriched to 60%, a level that sits uncomfortably close to weapons-grade material. Any deal between the two sides would almost certainly require that stockpile to go somewhere, and “somewhere” needs to be a place both sides can trust.