>and US and their trade partners enjoy safe trade routes
Bingo, and that's from the Navy and the U.S. Coast Guard actively patrolling GLOBAL waters.
Maritime piracy alone is a considerable economic threat, yes in the 21st century. An estimated 2 BILLION dollars a year is spent on naval operations just off the coast of Somalia (PDF WARNING - PDF WARNING - PDF WARNING http://www.ics-shipping.org/docs/default-source/Piracy-Docs/... )
In this article from 2014 ( https://worldmaritimenews.com/archives/134829/annual-global-... ), again just Somalia, "The OEF estimates the total cost of piracy off the coast of Somalia at US$7–US$12 billion in 2010; US$6.6–US$6.9 billion in 2011 42 and US$5.7–US$6.1 billion in 2012".