Gotta dig on this, but we've learned much thru Q about ports being used for trafficking. There is also the danger of what comes in from our enemies' ships. Inspections on foreign ships is negligible, too. And China runs too many ports - like Long Beach, CA's, Panama Canal.
Here's some sauce:
https://amac.us/with-acquisition-of-california-port-china-broadens-influence-on-us-commerce/