For the past half century, China has lived by the mantra, “five principles of peaceful coexistence” that advocates for a foreign policy of noninterventionism. Aside from a few instances, China has maintained a relatively neutral foreign policy. One benefit of this 
strategy is that China was able to maintain commercial interests abroad with countries that are shunned by the rest of the world. It also distinguished the nation as a developing country from the rest of the Western powers. When China has taken part in diplomatic tasks, it usually takes a secondary or reluctant role in the interactions.
Lately however, China has begun to spearhead programs intended to promote peace in the middle east. China is working with Pakistan and the Taliban to facilitate a political settlement in Afghanistan. With an increase in terrorism within China’s heartland, China has realized the importance of stabilizing radical Islamic groups in the middle east.
As one of the largest superpowers in the world, China has now realized its role in the global geopolitical climate. China is able to use military and economic negotiations to promote peace in troubled economic regions.
Source: http://www.nytimes.com/2015/03/27/opinion/chinese-foreign-policy-comes-of-age.html
China’s realization that they are a superpower may have it’s benefits in the geopolitical climate, but they have also been using their power to try and show that the regulation of the internet is needed, and this has been met with a lot of criticism.
China’s diplomatic intervention also appears in Africa region as well. Since 2013, China has been intervened in internal affairs of South Sudan which is in the middle of a civil war. China’s realization of its role in the world might have brought changes in their diplomatic stance but it can also be interpreted as one way protecting its over billions of dollars worth investment in South Sudan’s oil exploration project.
China did invade Vietnam in 1979; the Vietnamese drove them out. The tale of how the two countries reestablished comparatively cordial relations is a fascinating tale, told by Brantly Womack in China and Vietnam : the politics of asymmetry. Cambridge University Press, 2006. (Leyburn DS740.5.V5 W65).
China is aggressively claiming several reefs off the shores of the Philippines, Vietnam and Malaysia, as well as sparring with Japan over the Senkaku Islands. In the case of the latter, the aggression led to a ship collision. They are pushing the boundaries of “peaceful coexistence” with their immediate neighbors. Because of long-standing border disputes with India, they have courted Pakistan; they share a border with Afghanistan, which was carved into its odd shape to serve as a buffer between the Persians, the British, the Chinese and the Russians. Perhaps China is sufficiently neutral to serve as a broker. In any case, can you come up with additional details on the latter? I’ve heard nothing of it.