The Russian government made headlines in 2016 when word got out that Moscow wanted to buy five combat dolphins. But as Slate noted, “Assembling a dolphin army wasn’t the Russians’ idea. It was ours.”
In the ’60s, military researchers realized dolphins were highly trainable, with diving skills and finely-tuned sonar. This led to the U.S. Navy Marine Mammal Training Program, which boasted more than 150 dolphins at its peak in 1995.