To say that an Attorney General is confident in his own indictment is
typical at best.  What prosecutor is going to say that the defendant is
innocent of the charges?
 
In regards to this issue, Redman's _Ezra Pound and Italian Fascism_  covers
it beautifully and I suggest that anyone professing some knowledge of the
life's events of Pound ought have a look at the book.
 
Redman presents the statements of Judge Conrad L. Rushing and legal
philosopher Herbert Morris who posit that the prosecution's case was so
tenuous that the prosecutor easily accepted a plea of insanity rather than
go to trial.  But originally the ins. plea was merely a legal tactic to
postpone the trial for a few years after the war to let people cool down.
Judge Conrad expresses the opinion that had the case gone to trial, the
sentence would have (1) been nowhere near as cruel as his stay at St.
Elizabeths and (2) allowed Pound the opportunity to pay his debt to society
(something that his 12 year stay at St. Elizabeth's could never do).