When all your assets are tied to your currency and your currency tanks life gets hard. Having foreign assets you can divest and spend is useful, and is one of the things (along with oil transactions) that props up the US dollar's value. Because everyone ends up buying T bills as a simple way to hold assets denominated in dollars.
Japan in the 80's simply started buying up America (real estate, businesses) because of our recession, and a lot of people already worried about automobile manufacturing had a whole new set of worries. But then Japan had its own recession in the 90's and a lot of divestiture happened.