It is all about suppressing the truth. Bolton knows where all the skeletons are buried and how they got there.
WASHINGTON — The White House has issued a formal threat to former national security adviser John Bolton to keep him from publishing his book, “The Room Where It Happened: A White House Memoir,” sources familiar with the matter tell CNN.
He he, yet no actual evidence that such a threat actually occurred.
"sources familiar with the matter tell CNN"
Until the letter is produced, or some other definitive evidence is forthcoming, I remain skeptical since the Bolton claims were never a "bombshell', certainly not a impeachable offense anyway, since ALL the aid was already sent by September 15 of last year, without any actual Quid Pro-quo activity as
PUBLICLY stated by Two Ukrainian Presidents, who clearly stated they were NOT pressured by Trump.
LINK
It is at best His word against Trumps word, not good enough in a trial, and from a proven hostile "witness" since he was fired/resigned over serious policy disagreements with that same man he is accusing.