Amb to Ukraine Volker, Resigned, Was Volunteer Amb, Real job Exec Dir at McCain Inst. & worked as McCain's Aide - Rudy G tweeted about him as well. Not sure if he was the whistleblower, but he played some role for sure.  Amb. Kurt Volker, US special envoy to Ukraine, has resigned from his post. Volker, who served in the role on a volunteer basis, is executive director of the McCain Institute for International Leadership Volker is a former foreign service officer who also worked as an aide to late Sen. John McCain and had extensive experience in the NSC and at the US Mission to NATO before serving as US ambassador to NATO from 2008 to 2009. He was tapped for the job in July 2017 I can confirm but looks like this story was first broken by Arizona State University’s school paper (McCain Institute he heads is a part of ASU) Source: https://twitter.com/RobbieGramer/status/1177720646744199168 Rudy's Tweet - https://twitter.com/RudyGiuliani/status/1177346278004539392 Update: Volker also runs the McCain Institute, which was deeply involved in spreading Russian collusion hoax nonsense throughout government in late 2016 and 2017. The McCain Institute’s David Kramer, for example, gave the dossier to BuzzFeed. https://twitter.com/seanmdav/status/1177727890378694661 Update 2: Rex Tillerson appointed Volker in July of 17. Interesting. https://twitter.com/chiIIum/status/1177756921585192960