Does the Post-WHO-Exit IHR Architecture Survive Operational Stress?

Plain read: January 2026, the United States formally exited the World Health Organization under Executive Order 14155. The open question: in the next real-world cross-border outbreak, would international health coordination still work, or would the absence of US scaffolding cause measurable degradation? The MV Hondius hantavirus cluster (April-May 2026) became the first non-trivial test. The verdict (Report #84): the system worked. Symptom-onset to the World Health Organization notification took 26 days - faster than the average across five comparable pre-exit benchmarks (MERS Korea 9d, Diamond Princess 14d, Marburg Equatorial Guinea 40d, measles Samoa 45d, Ebola West Africa 90d; mean 39.6 days, z-score -0.42, 33rd percentile). South Africa NICD sequenced the virus. Senegal's Institut Pasteur de Dakar tested follow-up samples. ECDC deployed an EU Health Task Force expert directly to the ship. Africa CDC coordinated continental response. Switzerland, Singapore, Canada, the UK, Japan, the Netherlands, and Spain all integrated tracing. The US ran a parallel bilateral track for residents in five states (GA/CA/AZ/TX/VA) by direct intelligence sharing with European and African counterparts, conspicuously routing around the World Health Organization. The H1 thesis (IHR coordination degrades without US) is empirically falsified at this dimension.