The Prohibiting Russian Uranium Imports Act, signed into law in May 2024, bans Russian low-enriched uranium starting in 2028, with import caps ratcheting down each year before then (Congress.gov, H.R. 1042). Moscow retaliated with its own export ban on TENEX enrichment services. Every headline about "decoupling from Russia" fixates on enrichment — the SWU (separative work unit) capacity that turns 4% enriched uranium into reactor fuel. But enrichment isn't the scarcest link. Conversion is: the industrial step that turns mined and milled U3O8 ("yellowcake") into UF6 gas, the only form enrichment plants can actually process. Cameco itself puts Russia's global market share at 14% of uranium supply, 27% of conversion services, and 39% of enrichment — meaning conversion, not enrichment, is where the West is proportionally most exposed and where its own alternative capacity is thinnest. There are only three primary Western commercial converters on the planet, and losing Russian conversion tonnage hits a market with almost no slack to absorb it.