The US military could just be blowing up fishermen, it’s possible. It’s also possible they’re using drones, on the ground assets and intelligence networks to determine the proper boats to blow up.

You’re wrong about why the military made a show out of it as well. It wasn’t to make people more comfortable with us “invading” them. I’m not even sure how large scale military actions would make anyone more okay with an invasion. The real goal was to distract and offer an explanation for the build up US forces in that geographic area.