Bob McNally does not scare easily. The former White House energy advisor and founder of Rapidan Energy Group has spent decades navigating oil-market crises, from Gulf Wars to OPEC standoffs. So when he describes the current Strait of Hormuz closure as a “guaranteed global recession” if it persists, the energy world pays attention.

Rapidan’s warning, issued on May 21, frames the situation bluntly: if the strait remains closed through August, the resulting economic downturn could rival the 2008 Great Recession.

Why the Strait of Hormuz matters more than almost any other waterway

Roughly 20% of global oil transit flows through this narrow passage between Iran and Oman. Rapidan has characterized the ongoing disruption as the largest to global oil markets since the 1956 Suez Crisis. The current closure has already been running for several months, and the supply shock is compounding with every passing week.

Brent crude prices have climbed nearly 40% above pre-closure levels. Analysts warn that unless the strait reopens swiftly, oil could exceed $147 per barrel. For context, oil hit that exact level in July 2008, right before the global economy cratered.

Rapidan is not alone in sounding the alarm

Citadel CEO Ken Griffin weighed in during April, offering his own assessment: a shutdown lasting six to twelve months would inevitably trigger a global recession. McNally first raised the warning publicly back in March, arguing that prolonged disruption to the strait would create unprecedented consequences for global oil supply.