Japan's slowing-China problem may seem startlingly new, but it's really 30 years in the making.

Of all troubles Prime Minister Shinzo Abe thought he'd have with China, another recession wasn't on the list. Quarrels over history, disputed islands and influence in Asia are suddenly taking a back seat to Tokyo's vulnerabilities as China drags Japan into its second recession in three years. As China hits a wall, Japan is up against one of its own creation — dating back to 1985.

That was the year, more or less, when the myth of Japanese invulnerability took root. When the then-Group of Five nations asked Tokyo in September 1985 to let the yen soar in global markets, Prime Minister Yasuhiro Nakasone figured why not — Japan was unstoppable. Tokyo believed it had found the Holy Grail of prosperity, while its companies were changing the world with the Walkman, video games and high-reliability cars. Decades after it all went wrong, Tokyo is desperately trying to reclaim that moment.