Here is the relevant text of the 25th Amendment:
I've highlighted the most relevant part for our purposes here and now. I'm highly skeptical that anyone could demonstrate constitutional levels of physical or mental incapacity, rather than consistent inclinations towards despotic and corrupt behaviour which were already obvious back in 2016.
When exactly did Trump give the directive to terminate USKFTA and to whom did he give that directive?
He denies doing so, if I'm reading
this transcript correctly.
Hard to say Cohn violated his oath or neglected his duties by taking away a directive which the President evidently had no intention of signing.