NIKKEI vs S&P 500

For years I've made it no secret that I thought the US was going to follow Japan into a so called lost decade -- of course it's now more than a decade.

With the US stock market now apparently in a free fall I though this chart I've been keeping for years would prove of interest. In particular, note how nicely the two stock market major peaks and troughs seem to coincide. Is it more than just an interesting coincidence?