Rows between China and the US are simmering since the latter sent a surveillance plane to watch over a few China-controlled islands which are under construction in the South China Sea.

The Pentagon remained stiff after the incident and claimed that it might deploy military troops within 12 nautical miles of the disputed islands. Concerns have grown with many scholars, experts and policymakers starting to talk about the odds of a military confrontation between China and the US, and the conditions under which it will be waged.

The US is raising the risk of physical confrontation with China recently. Both sides are unwilling to compromise in strategic purposes, then tactically, Washington will draw closer to a tipping point. The trend will lead to a dangerous outcome if China does not and will not allow excessive concessions. Thus, it is essential that both sides should show their bottom lines to each other, and see if one can respect the other on these.

For China, one bottom line is that the reclamation of these islands must be finished no matter what. If the US sets its bottom line on the condition that China must stop its construction work, then military confrontation will start sooner or later.

China has another bottom line, which is asking the US to respect its territorial sovereignty and maritime interests in the South China Sea while the US has clearly expressed that freedom of navigation is its key interest in this region. In this regard, both sides still have leeway to maneuver.

The US is still vague about its real purpose in the South China Sea. If it is only for some sabre-rattling or harassment purposes, China will exercise self-restraint in general terms, which will hardly trigger physical competition. But if the US wants to teach China a lesson by provoking and humiliating and even disregards the outcome of physical confrontation, China will have no choice but to engage.

Washington should give enough space to China's peaceful rise, and China should share US concerns about the rise. As long as both sides are unwilling to move toward a showdown, risks are still under control. Both sides are able to deal with any emergencies peacefully and effectively under this consensus.

The South China Sea is not everything in Sino-US relations, but their bilateral cooperation will more or less be hampered by the Pentagon's aggression. Washington should be aware that it does not have real advantages in the face of China's determination and perseverance to protect its sovereignty. When the Chinese say something is a "paper tiger," this is it.