That's not correct. A company would have been able to sue only if the country was enacting a policy that would allow them to unfairly take advantage of an inves

That's not correct. A company would have been able to sue only if the country was enacting a policy that would allow them to unfairly take advantage of an investor. e.g. if the country made a deal that allowed a factory to be built in their country and then enacted a policy (tax or otherwise) that would force the investor to halt operations in their country for sole the purpose of taking control of the factory. Without that part of the trade deal there would be no stoping a small country from what is essentially stealing from a international company. Before trade deals those types of disputes were usually settled with armed conflict.