From a Washington Post interview with Senator Elizabeth Warren:
You can’t envision even in theory a way to structure ISDS that would assuage your concerns?
WARREN: Once a group of independent arbiters, whose decisions cannot be appealed, can issue a money judgment of any size, then the ISDS problem arises….Here’s what you could do. If corporations had to go through the same procedures that anyone else has to go through to get the trade deal enforced, then the problem wouldn’t exist.
Now, if a labor union says, ‘Vietnam promised not to work people for a couple of dollars a day, and to raise working conditions, and then failed to do it,” they have to get the U.S. government, through the trade rules, to go to Vietnam and prosecute the case. If corporations had to do the same thing, then it would be a level playing field…ISDS gives a special break to giant corporations, a break that nobody else gets.
It sounds like she would be fine with international investment obligations if state-state procedures replaced investor-state. I suspect she might also have concerns about the fair and equitable treatment and expropriation obligations, but she didn't mention those here.