Direct from the horse's mouth. US military operations in SCS is not about Freedom of Navigation, it is more about clinging to US Hegemony. Contrary to the rhetoric, historical trend indicates as China becomes richer and more powerful, it is US hegemony which is less tenable.
according to Military.com US Naval, Air Maneuvers Become 'New Normal' in Asia Pacific
“The rebalance is a lot more than ,” he said after addressing sailors at Sub Base New London in Connecticut. “It’s a whole program of enhanced activities in the Asia-Pacific — by the way, diplomatic and economic as well as military.”
“It is shifting forces to that part of the world, it is modernizing forces in that part of the world, it is the enormous pattern of bilateral and multilateral exercising we do, partnerships with the militaries in the region who are very eager to work increasingly with the United States,” he said. “It’s a whole lot of things that are intended to keep the system of peace and stability in the Asia-Pacific that served the region so well for so long.”