Submarines, it seems, are the focus of navies in the Far East (or is it now the Far West, in terms of our view of the Pacific).
China is more and more dependent on foreign trade, and therefore shipping. Its reliance on shipping mandates a more powerful navy, which is in fact happening. China's latest large ship is an aircraft carrier, Liaoning, as it extends its navy's reach globally.
But even more interesting is the reaction of China's smaller Pacific neighbours. Vietnam has acquired its first submarine, a Russian-made Kilo. Japan and South Korea are adding significant numbers of submarines to their fleets. Malaysia is buying submarines. Other Pacific nations such as Australia and India are well into the submarine business, and Russia is churning out Kilos for external sales.
The point of all this is that countries without the ability of China, Russia and the US to build and man large surface fleets are turning to the submarine to neutralize the large powers' threats in times of tension or war.