Answer:
Step-by-step explanation:
Starting with China's Northern border, it borders Mongolia and Russia. Mongolia is a sparsely populated and flat nation, while Russia is a nation whom China has rocky relations with. China also has interest in Russian territory North of China which causes tension.
Next, China's Western border is shared with Central Asian nations as well as India. India and China have had many territorial disputes in the Kashmir region and elsewhere, and are not on the best terms. Also, many of the Central Asian nations are rich in oil, which causes larger nations such as China and Russia to compete over their influence.
China's Eastern border, although facing the ocean, is surrounded by NATO and American allied nations, who obviously aren't fond of China. Japan, South Korea, and Taiwan form a chain just outside China's coast and all host American military bases. It is also important to note China's interest in the South China sea and their disputes with other nations regarding territorial waters. China imports many important resources through straits controlled by Singapore and Indonesia who are more likely to side with Western powers in the event of a conflict, which causes tension and concerns for the Chinese government.