History teaches us few wider lessons. But there are rare exceptions. One of these is that for a nation to put its former leaders on trial is never straightforward. Although such cases are rare, when they do occur they frequently involve the pushing of pre-existing legal boundaries and the reshaping of constitutional norms and assumptions. The evolution of the doctrine of crimes against humanity after the Nuremberg trials in 1945 is the most significant modern example of this.
Both at the time they occur and subsequently, the arguments that surround trials of this kind are almost inescapably political to a significant degree. That was true of the trial and execution of Charles I in 1649, an event that divided England then; and some of those divisions of the 17th century can still be felt today. But it will unquestionably also be true of the trials of the former US president Donald Trump, of which the latest step is due to be taken in Atlanta on Thursday.
