The news report that China's military has a cyber warfare unit in Shanghai dedicated to hacking into the computer systems of American institutions is chilling, but not surprising.
The Chinese Foreign Ministry denied the information in Tuesday's New York Times, which reported that a 60-page study by Mandiant, an American security firm, tracked the hacking activity to the area of a 12-story office building controlled by the military on Shanghai's outskirts.
By hacking into untold numbers of U.S. information systems involved in everything from Coca-Cola to electrical grids, water systems, railroads and governmental agencies, the People's Liberation Army has demonstrated the capacity not only to steal secrets but also to disrupt operations. The PLA has been doing it for years -- Mandiant says since 2006 -- and the suspicion is that a large number of America's commercial secrets have been pilfered and passed along to Chinese companies.
Even Americans who can't imagine a war between the United States and China must be alarmed by this development. The fact that Chinese military hackers could disable, in a wartime situation, critical pieces of U.S. infrastructure or even military readiness has to be disturbing.
On the other hand, just as with nuclear weapons and the notion of mutually assured destruction, it is likely that America's cyber warriors have drawn an equally lethal bead on Chinese capacities and infrastructure.
It is tempting for Americans to react with anger and consider retaliating with a cyber attack on Chinese systems -- or at least on the PLA hackers' Unit 61398, made infamous by the Times report -- comparable to what the United States and Israel did to Iran's nuclear facilities with the computer virus Stuxnet.
A more mature response would be to see China's hacking activities as part of the reality of 2013. Nonetheless, there should be earnest, quiet talks on the subject between President Barack Obama and incoming Chinese President Xi Jinping as soon as possible. This is not an area in U.S.-Chinese relations where ambiguity can be allowed to reign.