China's build up for war in the billions they are investing in their military has many countries in Asia quite worried. Taiwan, the Philippines, Japan, South Korea, Singapore, Malaysia and others are all worried that China is growing its military so in the future it will dominate the entire part of that region and one-forth of the world.
In fact with all the Middle Eastern problems and Machiavellian tactics of switching sides it appears that China is hoping no one is noticing its quick buildup. Not only is China building its military, but now it has become a seller of military hardware and selling to such countries as Iran, which sponsors international terrorism and has promised to blow Israel often out. You can immediately see the problems that exist.
In addition to this Chinese generals more than once have said that if the United States were to interfere with the reunification of Taiwan by force, then China would retaliate against the United States with nuclear weapons. You can understand why the United States of America is shifting much of its forces in the Pacific as a hedge against the Chinese Sun Tzu political intimidation tactics that such theories are indeed known for.
Request is still remains if China has no enemies and certainly not the US its largest trading partner, then why is China need the second-largest military in the history of the human species. As Einstein said;