The principal focus of, and driver for, China’s military modernization in the near term appears to remain preparing for potential conflict in the Taiwan Strait. However, official documents and the writings of Chinese military strategists suggest Beijing is increasingly surveying the strategic landscape beyond Taiwan. Some Chinese analysts have explored the geopolitical value of Taiwan in extending China’s maritime “defensive” perimeter and improving its ability to influence regional sea lines of communication.China's push for a blue water fleet is not welcomed in the region. Especially by those who have regional sea lines of communication that China might "influence." (Not to mention the Taiwanese, who would not be eager to be a Chinese base for power projection.) We are redeploying assets to the Pacific and building up Guam. Japan is building up its fleet and air power. Australia is doing the same. Taiwan is, too. And India is looking east with their fleet. Oh, and South Korea is heading to sea, as well:
South Korea is spending $850 million to build a naval base on Jeju island, which is 90 kilometers south of the South Korean coast. The base will provide piers and other facilities for up to twenty ships and submarines. The island is astride the vital straights separating South Korea and Japan. Through these waters, most of South Koreas maritime trade moves. The new naval base will make it easier to protect that traffic. The new base also makes it easier for South Korean warships to get to small islands in the area that are claimed by South Korea, Japan and China. The new base will be ready for use in seven years.
As long as Chinese power projection didn't reach out much beyond about 50 miles from China's coast, this wasn't an issue. But South Korea is a major trading power with shipbuilding industries thriving on foreign orders. They just launched a large Aegis-equipped destroyer for their growing fleet.
With a large GDP reliant on trade, South Korea now has the need to have open access to the sea. With a large GDP, South Korea has the means to protect those sea lines of communication. And with China heading out to sea, South Korea has the impetus to build a fleet capable of defending those sea lines of communication.
China is surrounded by actual enemies or potentially hostile neighbors and I'd never trade places with them. As China builds up, others are reacting. Like any communists, they don't understand that there is no free lunch. Not ever.