America and its allies are facing a growing submarine threat in East Asia. Two decades ago, with the Cold War over, the United States Navy did not have much submarine competition in East Asia. The Russian Far East fleet was rapidly falling apart because of the defense budget being cut more than 80 percent. China and North Korea, traditional Russian allies, had a motley collection of older Russian subs. The U.S. and its allies (Australia, South Korea, Japan, Taiwan, and Singapore) not only had more subs but they were of more modern design and construction.
That has changed. The U.S. Pacific Fleet currently has 39 subs in the Pacific, while the allies have 50 for a total of 89. In contrast China has 55 and its allies 40. North Korea also has over 70 mini-subs, which are only a factor close to the North Korean coast. All of North Koreas subs are either ancient or poorly maintained and operated by ill-trained crews. But China and Russia are enlarging and improving their submarine forces in the Pacific.
Over the next two decades the trends are in favor of China and Russia. China is in the process of increasing its sub fleet to 80 boats in the next decade. The Russian fleet, however, continues to shrink. By the end of the decade the Russians will have about fifty subs in service, some 30 of them will be nuclear. Three decades earlier they had 180 nuclear boats. All of those are gone now and the thirty that will remain at the end of the decade are new construction, most of them less than ten years old. That assumes the Russians keep to their current construction plans and shift most of their nuclear boats to the Pacific. The Chinese subs will also be largely new construction. But so will the subs of the Americans and their allies. The U.S. is moving more of its subs to the Pacific and Chinas neighbors are upgrading their submarine fleet.
China will thus still have about as many subs as its potential opponents but the quality gap will be closed somewhat. The American block will still have an edge but it is shrinking. This is what China intends to have happen. In a few decades China expects to close the quality gap. The Chinese strategy is one of gradual progress and so far it is working.