If China wanted to mobilize and weaponize its merchant ships for war, it would total over 172,000 that America would have to face. See also HERE for further information.
In a future conflict, America could find itself outnumbered and outmaneuvered on the high seas, according to a 2015 report on maritime security published by Hawaii Pacific University.The authors of this report are Capt. Carl Schuster, former director of operations at the U.S. Joint Intelligence Center Pacific, and Dr. Patrick Bratton, associate professor of political science at Hawaii Pacific University. They point out that “the United States has adopted an ‘abandon ship’ policy towards the crucial merchant maritime industry” and let the number of merchant ships flying an American flag dwindle to the lowest number since the end of the Spanish-American War.
Global Geopolitics 