What can China learn from the US sea drone strike on an Iranian submarine base?

Chinese military analysts are urging the People’s Liberation Army (PLA) to rapidly strengthen harbour defences after the United States carried out its first combat strike using unmanned surface vessels (USVs) to destroy an Iranian submarine.
US Central Command released footage on July 13 of what it said was the first combat use of American sea drones. Three vessels were shown striking an Iranian base, reportedly destroying one Ghadir-class midget submarine.
The Iranian-made submarine has an...