You basically need the world to decide that EMEA/JAP markets are collectively stronger than the US stock market, and to collectively move their capital outside the US to be deployed in EMEA/JAP. Moves away from Mag7 to US value stocks will be captured by the US stock market index funds; moves into commodities will be seen as opportunities to buy the dip before a market rebound. You can view attempts by US private equity to purchase real estate as attempts to hedge against overvaluation in US markets, but if the US has another Great Depression, those real estate purchases won't be able to fetch high rents or prices anyway.
In short, just follow the normal advice, which is not to put all your money into US domestic stocks, but to also purchase foreign stock market index funds, which help to hedge against the risk of the entire US stock market crashing. In the long run, US index funds are still a good investment - US courts still are quite powerful to settle contract disputes, the US does not have capital flight controls, and American business culture is still one of the hardest working, greediest forces on the planet - a Great Depression v2 would not change that.