A good start for actually holding people accountable in the US would be prosecuting the entire chain of command responsible for blowing up unarmed South America

A good start for actually holding people accountable in the US would be prosecuting the entire chain of command responsible for blowing up unarmed South American boats and then murdering the survivors. That one's concrete, proven to have happened, and illegal under multiple standards of law, so if we can't at least make that happen anything else is unlikely.