21ST CENTURY ASW: Navy Plans Hammerhead Mines To Box In Chinese, Russian Subs. “The Navy is inching closer to fielding a new anti-submarine mine designed to deploy from underwater drones and loiter for weeks at a time around critical chokepoints, looking for enemy submarines to sink.”

China’s naval problem is that their best ports are all behind strategic chokepoints, a problem “Hammerhead” would compound.

Of course, that all changes if Beijing were to take Taiwan.