The Chinese government is agitated, perhaps justly so, because Japan, once one of the world's great naval powers, has launched its largest warship since World War II.
Japan's constitution and postwar surrender agreement limit its forces to self-defense. And the ship, the "Izumo," presses and even bursts the envelope of that agreement.
The Izumo is a destroyer, but only because the Japanese navy calls it that. The ship has a flat deck more than 800 feet long, significantly longer than that of a U.S. World War II-era escort carrier.
The Izumo has a capacity of 14 helicopters and will be used in anti-submarine warfare, coastal surveillance and transporting supplies and personnel in response to natural disasters like earthquakes and tsunamis.
You do not have to be a naval architect to see that the Izumo's huge deck could be used for the vertical takeoff and landing of fighter jets like the Harriers and that a flight deck modified for catapults could launch conventional fighter jets.
It is another step in what seems to be a quiet Japanese effort to build up a powerful and credible military, one capable of more than purely defensive missions.
If this worries the Chinese, they have only themselves to blame. The Chinese have aggressively been building up their navy, which includes one carrier they bought from the Russians and refurbished and another carrier of their own design.
Moreover, they have been aggressively patrolling and claiming sovereignty of islands scattered all over the China Sea that are claimed by China, Japan, Taiwan, the Philippines and Vietnam.
Many of the islands are inconsequential and uninhabited, but they give the owners rights over fisheries and oil and minerals within the territorial waters. And nothing says ownership like a fleet of aircraft carriers, even small ones.
This seems like one of those boundary problems that could be thrashed out by the striped-pants crowd, but the strategic planners regularly list the South China Sea and its barren islands as one of the world's flashpoints.
The last thing that part of Asia needs is a naval arms race. If a race there is to be, Japan is showing that it will not be one-sided.
The author is an editorial writer for Scripps Howard News Service (www.shns.com).