“To get the full diversification benefits, we recommend that you consider investing about 40% of your stock allocation in international stocks and about 30% of your bond allocation in international bonds.”
Does not mean 40% of your portfolio. Unless your portfolio is 100% equities.
Makes sense to me if it’s mostly weighted for emerging markets. That’s still 60% of your stocks in a single country, remember. Emerging markets have fundamentals like PE ratios half of the US equivalent. I’m not so bullish on developed markets though. Future tech out of Europe (most of developed) looks bleak.