One of the major goals of North Korea’s nuclear force modernization is to diversify its systems for delivering nuclear weapons. To this end, leader Kim Jong Un has overseen the introduction of everything from new cruise missiles to new basing modes for short-range ballistic missiles, including lake-launch missiles and silo basing.

This broader push for diversification has now taken Pyongyang decidedly into the realm of the exotic: On Friday morning, North Korean state media revealed that the country has developed an “underwater nuclear attack drone.” 

Designated “Haeil” and described as a “secret weapon,” the