For me CAPE valuations are much more important than yearly PE's
The valuable links from Brooklynguy are showing that the US market currently again has a high valuation. (Currently still CAPE 24 after the small sell off)
Maybe that doesn't matter that much in 30 years from now but it matters a lot in the next 5-10 years.
With the exception of 1996 those high valuations where always sold off in the years ahead (from 1902 to 1921, 1929-1942 and 1966 to 1982)
Other markets with similar growth and stability in the last 40 years already have lower CAPE valuations and from my perspective it make sense to at least diversify also in those (Singapore CAPE ~11 (!) Dividend yield ~4,5%) and Hong Kong CAPE ~13.5 Dividend yield ~4% )
Those numbers are historically pretty low for this stable and still growing (non commodity) countries.