FEDERAL RESERVE CHAIRMAN Alan Greenspan teamed up with Treasury Secretary John Snow to urge calm when they went before a Senate committee last week. Once again, politicians and policy wonks are up in arms about a foreign takeover of an American company, in this case the attempted acquisition of Unocal by China’s National Offshore Oil Corporation (CNOOC). To those who remember the hysteria that greeted Japan’s purchase of Rockefeller Center, the jewel in the crown of New York real estate, in the late 1980s, “It’s déja vu all over again,” to borrow from the Yankee sage, Yogi Berra.

That might just be dangerously wrong. The current Chinese takeover movement is different from the earlier buying spree by Japanese companies. Japan was not a rival for influence in Asia, or in the world; China is. Japan was not a major competitor for scarce resources such as oil; China is. Japanese companies were privately owned; China’s acquirers are state-run entities. Japan is a democratic country, and by and large an American ally; China most definitely is not. Japan did not engage in the wholesale theft of intellectual property, China does. Japan did not buy strategic assets: ownership of New York real estate has no implication for national security; ownership of oil resources does.