The idea is that if citizens could sue foreign countries, then those countries' assets in US jurisdiction could be seized.
In the case of SA, there are the treasury bonds that they are talking about selling. Considering the all-encompasing dollar-based banking system, the US in particular would be very skilled at getting foreign nation assets in rulings.
I think the reasoning behind it historically is about maintaining proper diplomatic relations. The executive is in charge of foreign relations, not the judicial system. There's probably some arguments about standing too, and jurisdiction. But I think it's mainly the diplomatic angle.
In the case of SA, there are the treasury bonds that they are talking about selling. Considering the all-encompasing dollar-based banking system, the US in particular would be very skilled at getting foreign nation assets in rulings.
I think the reasoning behind it historically is about maintaining proper diplomatic relations. The executive is in charge of foreign relations, not the judicial system. There's probably some arguments about standing too, and jurisdiction. But I think it's mainly the diplomatic angle.