And fourth, the debut of pumpjet-equipped SSNs would empower Beijing to mount a standing presence in faraway recesses of the South China Sea and Indian Ocean for the first time. Diesel boats have ventured into the “far seas” in recent years, but they must put into port at regular intervals to refuel. This exposes them to detection. SSNs can remain at sea, and undersea, as long as their food and stores hold out. The crew—not the engineering plant—thus constitutes the limiting factor on a nuclear-powered boat’s at-sea endurance. The Indian Navy has taken notice of PLA Navy forays into India’s home region, and grasps the implications of high-tech Chinese SSNs cruising the Indian Ocean. Indeed, some Indian mariners deem such a presence a red line for competition between the two navies.

It can be no accident, then, that there’s an antisubmarine flair to this summer’s Malabar exercises among the Indian Navy, U.S. Navy and Japan Maritime Self-Defense Force. All three navies dispatched aircraft carriers for maneuvers for the first time. The Japanese flattop JS Izumo is a euphemistically dubbed “helicopter destroyer” optimized for hunting submarines. What hostile subs may lurk in the Bay of Bengal, where the exercises are underway, apart from China’s? Hider-finder competition, it seems, has come to the Indian Ocean.

Does new engineering technology herald an age of Chinese maritime supremacy? Of course not. Carl von Clausewitz portrays martial strife as constant struggle between “wrestlers” striving to “throw” each other for strategic gain. That goes for acoustic one-upmanship as well. One contender innovates; the other resolves to outdo it. It appears, consequently, that more equal undersea competition lies in store. To prepare for it, U.S. Navy submariners must learn to think of PLA Navy subs not as prey to be devoured by American predators but as worthy foes, capable of some sub hunting of their own. The silent service must adjust to the new, old reality of peer competition beneath the waves.

The game’s afoot.

James Holmes is professor of strategy at the Naval War College and coauthor of Red Star over the Pacific (second edition forthcoming 2018). The views voiced here are his alone.

Image: Chinese sailors salute on top of a submarine during the fleet's review of the China-Russia joint naval exercise in the Yellow Sea April 26, 2012. Chinese and Russian warships concluded a live ammunition exercise on Thursday, following a no-weapon joint war game earlier the same day. Xinhua News Agency reported. REUTERS/China Daily​