Chinese Oceanography Echoes the Contest for Undersea Dominance Against the United States
In the Western Pacific, aircraft carrier strike groups may be the most obvious symbol of U.S. military power, and the reason why China is now working on its third aircraft carrier. But U.S. military leaders consider submarines to be its most important advantage against the great power challenge posed by China, a strategic threat emphasized in the Trump administration’s new National Security Strategy and National Defense Strategy. Because of the importance the United States places on its undersea advantage, one of the most important arenas of intensifying competition between China and the United States is also the least obvious — in marine laboratories and on oceanographic research and hydrographic survey vessels.
Since this work is often conducted by civilians, and almost as often has some dual-use application, it lacks the drama of a traditional arms race. But without mastery of the western Pacific’s oceanography, neither side can assert dominance over the undersea domain — granting freedom of action to its submarines, and denying it to adversaries.
A Look at the Numbers
While the United States fields a fleet of nearly 50 advanced, stealthy nuclear-powered attack submarines, China is increasingly asserting itself underwater. According to the U.S. Department of Defense, China currently has five nuclear attack submarines and 54 diesel submarines, and its fleet may grow to nearly 80 submarines by 2020. Chinese submarines reportedly penetrated rings of escorting destroyers and closely shadowed U.S. aircraft carriers operating in the western Pacific in both 2006 and 2015. In January of this year, a Chinese nuclear attack submarine sailed through the contiguous zone of the disputed Senkaku islands in the East China Sea, which Japan administers but that China claims as its own. Japan viewed the submarine’s transit as a serious provocation and escalation of the dispute.
The United States recognizes the challenge posed by China’s growing undersea fleet, but faces challenges to maintaining its own. In its most recent force structure analysis, the U.S. Navy said that it needs 66 attack submarines — nearly 40 percent more than it has today. Instead, it’s likely that the U.S. submarine fleet will actually shrink over the next decade. Shipyard constraints and the challenges of quickly expanding the skilled workforce needed to build submarines means that new construction probably will not be able to keep pace with the number of hulls that will have to be retired in coming years, let alone increase the fleet’s end-strength. As it is, the head of all U.S. forces in the Pacific has told Congress that the Navy can only meet half of his current peacetime requirements for submarine missions.
However, the contest for undersea dominance in the western Pacific is about far more than who has the most submarines, or even whose submarines are the most advanced. In the undersea domain, each side is listening for the other, either passively, for the sound a ship or submarine emits organically, or actively, by sending sound waves out and listening for them to bounce back off an adversary’s hull. Changes in water temperature, pressure and salinity affects how sound travels through it, so detecting and tracking an adversary while staying safely undetected oneself requires detailed understanding of the ocean depths, acoustics and the geography of the ocean floor.
