Taylor describes a ‘nightmare’ scenario, which would ultimately benefit Russia.

Page 209-210: “‘The nightmare’ is the scenario where President Zelensky goes out in public, makes an announcement that he’s going to investigate Burisma and the election in 2016, interference in 2016 election, maybe among other things. He might put that in some series of investigations.” “‘The nightmare was he would mention those two, take all the heat from that, get himself in big trouble in this country and probably in his country as well, and the security assistance would not be released. That was the nightmare. The Russians loving it. The Russians are paying attention. The Russians are paying attention to how much support the Americans are going to provide the Ukrainians.”

By Mr. Taylor’s account, in early September, he believed the worst-case scenario of Mr. Zelensky publicly promising investigations into the Mr. Trump’s political rivals would be if Russia were to benefit from quaking relations between the United States and Ukraine. Mr. Taylor had used the term “nightmare” in text message to others, but investigators asked him for further explanation. He added that he previously told Secretary of State Mike Pompeo that he would defend America’s support of Ukraine, but if the policy changed, he would quit. Mr. Taylor has yet to resign.

— Eileen Sullivan

Bolton ended a meeting between the U.S. and Ukraine when Sondland raised the topic of investigations.

Page 164: “When Ambassador Sondland raised investigations in the meeting, that triggered Ambassador Bolton’s antenna, political antenna, and he said, ‘we don’t do politics here.’

Mr. Taylor recounted to impeachment investigators how John R. Bolton, Mr. Trump’s national security adviser at the time, suddenly ended a July 10 meeting with American and Ukrainian officials when Gordon D. Sondland, the ambassador to the European Union, turned the discussion to investigations that Mr. Trump and Mr. Giuliani wanted the Ukrainians to pursue. Mr. Taylor said that he was not at the meeting, but he heard accounts from two people who were. At the time, Mr. Taylor was just weeks into his new job as the top diplomat in Ukraine, a position he hesitated to accept because of the circumstances around his predecessor’s removal.

— Eileen Sullivan

Bolton asked Taylor to bring his concerns on the aid to Pompeo. Pompeo appears to have listened.

Page 230: “He indicated that he was very sympathetic. I had known from earlier conversations with people that he was also trying with the two secretaries and the director of the C.I.A. to get this decision reversed. So he confirmed that and urged me to make my concerns known to the secretary again.”

Mr. Taylor’s recollection of his conversation with Mr. Bolton provides additional details about the circumstances under which Mr. Bolton stepped down less than two weeks later. In July, Mr. Bolton made clear that he was not on board with the shadow foreign policy campaign being pushed by Mr. Sondland and Mick Mulvaney, the president’s acting chief of staff. He also called Mr. Giuliani a “hand grenade who’s going to blow everybody up.” Mr. Bolton and Mr. Pompeo had been feuding for months, so asking Mr. Taylor to directly appeal to Mr. Pompeo makes sense.

Later in his testimony, Mr. Taylor rejected a suggestion that senior leaders at the State Department ignored his concerns about linking the American aid to a Ukraine investigation.

“Based on the concerns and the cable, Secretary Pompeo went to the White House, probably on a couple of occasions, you know in trying to have these meetings, and attempted to get the decision changed,” Mr. Taylor said, according to Page 315 of the transcript.

— Eileen Sullivan and Lara Jakes