A high-stakes clash between two of the world’s most influential billionaires is playing out in public, as Elon Musk and Bill Gates exchange barbs over foreign aid policy and humanitarian fallout. The feud ignited after Gates accused Musk—without directly naming him—of enabling conditions that could lead to millions of child deaths.

The Microsoft co-founder and philanthropist condemned his fellow billionaire for overseeing deep cuts to the U.S. Agency for International Development in the Trump administration.