Fiona Hill, former Special Assistant to U.S. President Donald Trump and Senior Director for European and Russian Affairs on the United States National Security Council, arrives on Capitol Hill on October 14, 2019 in Washington, DC.Alex Wroblewski | Getty ImagesWASHINGTON — House impeachment investigators on Friday released a transcript of testimony by President Donald Trump’s former top Russia expert Fiona Hill. In it, Hill vividly described the alarms that were raised by national security professionals in the White House who were aware of Trump’s policy towards Ukraine.Hill left the White House National Security Council shortly before the July 25 call between Trump and Ukrainian President Volodimyr Zelensky, during which Trump asked Zelensky for “a favor.”But her testimony offered a gripping account of the rising tensions in the spring and summer of this year between members of Trump’s national security council, led by former National Security Advisor John Bolton, and the small group of individuals who Trump directed to run a parallel foreign policy aimed at getting Ukraine to launch investigations that could help Trump politically.That small group consisted of Kurt Volker, Trump’s special envoy to Ukraine, Gordon Sondland, Trump’s ambassador to the European Union and Energy Secretary Rick Perry. The president instructed the three men to work closely with his personal lawyer, Rudy Giuliani.Hill testified that inside the White House, acting chief of staff Mick Mulvaney also played an instrumental role.In her testimony, Hill described Bolton’s growing frustration with Giuliani’s involvement in back channel communications with Ukraine’s newly elected government. “Giuliani is a hand grenade that is going to blow everybody up,” Hill quoted Bolton as having told her.The simmering tensions boiled over on July 10, Hill said, during a heated exchange between Bolton and Sondland at the White House. The conversation so angered Bolton that he directed Hill to notify the chief lawyer for the National Security Council about the pressure campaign on Ukraine to pursue investigations that Trump and Giuliani wanted.Hill also said Bolton told her to convey to the NSC attorney that Bolton was, “not part of whatever drug deal Sondland and Mulvaney are cooking up.”House investigators have invited Bolton to testify, but his attorney has signaled that Bolton would only do appear if he were to receive a subpoena, and a judge were to subsequently rule that he was required to comply with it.According to the testimony of current and former national security officials, Giuliani and Trump wanted Ukraine to announce two investigations: The first into a Ukrainian company, Burisma, on whose board the son of Trump’s political rival, former Vice President Joe Biden, once sat. The second investigation Trump wanted, according to Sondland and others, was into alleged interference by Ukraine in the 2016 presidential election.The allegations that Ukraine interfered in the U.S. presidential election in 2016 are unsubstantiated, and appear to be based on a conspiracy theory that serves as a counter-narrative to former special counsel Robert Mueller’s conclusion that Russia disrupted the U.S. race in Trump’s favor.Hill was the first former White House official to testify in the House impeachment inquiry, initially appearing on October 14.The House impeachment probe focuses on whether Trump abused the power of his office in his attempt to pressure Ukraine to investigate a political rival, and if so, whether those actions meet the standard for “high crimes and misdemeanors” deserving of impeachment and, potentially, removal from office.This is a developing story, please check back for updates.