So is there a high-tech arms race brewing in the Sea of Japan? Sort of, but let's not get too carried away. Stealth tech isn't exactly brand new--though it's still a closely held secret--and Japan isn't the only nation seeking it. Modern militaries see it as necessary for a cutting-edge air defense, and Japan is nothing if not modern. If other powers in the region are developing their own stealth technologies, it's unsurprising that Japan would do the same (especially factoring in the tenuous Sino-Taiwanese relationship and the always-unstable presence of North Korea just across the water).