Trump flings insults at John Bolton as Senate weighs subpoena: 'If I listened to him we would be in World War Six'

President Donald Trump hurled insults at his former national security adviser John Bolton -- who could be called to testify against him in the Senate impeachment trial.

Bolton revealed in his forthcoming book that Trump explicitly tied Ukraine aid to an investigation of Joe Biden, and Democratic senators -- and possibly some Republicans -- want to subpoena him to testify in the trial.

"For a guy who couldn’t get approved for the Ambassador to the U.N. years ago, couldn’t get approved for anything since, 'begged' me for a non Senate approved job, which I gave him despite many saying 'Don’t do it, sir,' takes the job, mistakenly says 'Libyan Model' on T.V.," Trump tweeted, "and many more mistakes of judgement, gets fired because frankly, if I listened to him, we would be in World War Six by now, and goes out and IMMEDIATELY writes a nasty & untrue book. All Classified National Security. Who would do this?"