When private insurers withdrew from the Persian Gulf within 72 hours of US and Israeli strikes on Iran, they did more than just re-evaluate risk; they effectively shut down the Strait of Hormuz without firing a single shot. This action significantly altered the landscape of maritime risk, highlighting the profound impact of geopolitical events on global shipping and insurance markets. The withdrawal signaled a severe escalation in perceived danger, making the region prohibitively expensive and risky for commercial vessels. This effectively created a de facto blockade, demonstrating the power of financial and insurance instruments in influencing international trade routes, even in the absence of direct military action.