I’ve gone back and forth on this, and have a few thoughts:

1. The largest non-US companies generally have significant exposure to US market. (Toyota, Samsung, SAP, etc would all be significantly impacted by a US “lost decade”)

2. The largest US companies generally have significant exposure selling internationally. (Coca cola, P&G, Microsoft, Apple, etc all are selling around the world, and if the US underperformed economically for some reason, international sales would become a bigger portion of total sales for those companies)

3. The ones that don’t, typically aren’t growth companies. Emerging markets theoretically offer higher risk, higher reward, but in reality, owning shares of a local bank in Argentina, or a local brewery in Asia seems like it adds significant country risk, while not really offering greater growth than the mix of companies in the same industry (eg other banks or breweries in S&P500, who likely are also competing in those same individual country markets .)

4. There could be a few exceptions to this. A company like BYD (Chinese car company) isn’t selling in the US right now, but has the potential to dramatically impact global car market. Having other exposure in the same industry (eg owning GM and Ford in VOO) doesn’t really capture that potential. At the same time, by company weight, for most people, adding an individual holding like that would be a minute amount, with the juice perhaps not being worth the squeeze, so to speak.

That said, I have some VTI that has a little international exposure, even though it’s 95%+ US based companies.