Imploded, no, but the Japanese economy basically peaked in 1991 and has yet to really recover (the so-called Lost Decade, although it's been well more than a decade now). As I understand it (this is before my time), in the 1980s, there was a widespread consensus that Japan was on the precipice of upstaging the US, much as there is a similar consensus nowadays that China is on the precipice of upstaging the US. That Japan failed to do so should augur difficulty for China to do the same.