Clio’s Musings – A propulsion disabler (PD) is a small, passive, torpedo-like device that serves as a cheap, non-lethal mine and torpedo warhead. The proposed munition’s purpose is to destroy a ship’s external propulsion or direction-control mechanisms, leaving the vessel stationary. Production of PDs is possible with today’s emerging robotics technologies.Future PD devices could be used in an autonomous swarm that combines the smallest explosive charge with the greatest disabling effect by attacking a ship at its most vulnerable point. Once PDs become widely available, they may well be the weapon of choice by all navies against civilian ships. Similarly, disabling an enemy’s naval ship rather than sinking it will almost always be the superior choice, certainly for the U.S. Navy. The logic that makes this so will compel adversary navies to make the same choice.