For nineteen days this June, the United States conducted an unintended experiment in the economics of technology restriction. On 12 June, the Commerce Department ordered Anthropic to bar every foreign national from its two most capable AI models; because nationality cannot be checked inside shared cloud infrastructure, the company shut both models down worldwide. The order was lifted on 30 June. The first lesson concerns the shelf life of a single-model restriction: competing and open-weight systems now trail the leading edge by months, not years, and the specific capability that reportedly triggered the June action was, by the developer's own account, reproducible on other available models. The second lesson concerns who actually bears the cost: banks, universities, and cyber-defenders on both sides of the Atlantic lost tools embedded in production workflows overnight, and more than 100 security leaders wrote to the government that the measure took the strongest models away from defenders without a corresponding loss to attackers. The third lesson concerns time as an economic input: the only way to comply was to switch everything off, and the only way to reopen was to negotiate the whole thing back on, taking nineteen days, with a set of vetted American organizations regaining access first.