Donald Trump is facing the most perilous crisis of his tenure after becoming only the fourth US president — after Andrew Johnson, Richard Nixon and Bill Clinton — to face an impeachment inquiry in the House of Representatives.
Over the summer, Mr Trump celebrated the conclusion of the two-year Russia investigation by special counsel Robert Mueller and criticised Democrats for pursuing a “witch hunt”, even though he was not exonerated by Mr Mueller.
But Mr Trump is facing a far more dangerous situation over a telephone call on July 25 — the day after Mr Mueller disappointed Democrats with his congressional testimony — with Ukraine’s president. During the call, Mr Trump urged his counterpart to open an investigation into former vice-president Joe Biden and his son.
Mr Trump has denied any impropriety and rejected suggestions that he withheld hundreds of millions of dollars in military aid to Ukraine to pressure President Volodymyr Zelensky into co-operating.
What to watch for
William Taylor, US chargé d’affaires for Ukraine
George Kent, deputy assistant secretary of state for European and Eurasian affairs
Marie Yovanovitch, former US ambassador to Ukraine
Jennifer Williams, an aide to Mike Pence, vice-president
Alexander Vindman, director for European affairs at the National Security Council
Kurt Volker, former US special envoy to Ukraine
Tim Morrison, White House aide with the National Security Council
Gordon Sondland, US ambassador to the EU
Laura Cooper, deputy assistant secretary of defence for Russian, Ukrainian and Eurasian affairs
David Hale, under secretary of state for political affairs
Fiona Hill, former National Security Council senior director for Europe and Russia David Holmes, political counselor at the US embassy in Kyiv, Ukraine
But a non-verbatim transcript of the call released by the White House and the publication of a whistleblower report that sparked the crisis has shown that Mr Trump attempted to use his office for political gain.
Over the next few months, six committees in the Democrat-controlled House will pursue an investigation that many believe will result in the lower chamber of Congress bringing articles of impeachment against Mr Trump.
While the chances are high that the House would back the charges, Mr Trump is banking on the fact that 20 Republican senators — a large hurdle — would have to abandon the president if he was to be convicted in a Senate trial.
The Whistleblower complaint
The complaint has been at the centre of the controversy that spurred the Democrats to launch the impeachment inquiry
Call transcript: President Trump and President Zelensky
Reconstructed transcript of the July 25 call between the two heads of state released by the White House
Text messages from Ambassador Kurt Volker to various Ukrainian and US officials
William Taylor’s opening statement
Testimony from the US’s top diplomat in Kyiv from October 22
Transcript of Marie Yovanovitch testimony
Transcript of the former US ambassador to Ukraine’s testimony from October 11
Transcript of P Michael McKinley testimony
Testimony of the former senior adviser to the secretary of state from October 16
Follow our impeachment inquiry coverage at ft.com/trump-impeachment-inquiry
THE TRUMP CAMP
US secretary of state
In his time as secretary of state, Mike Pompeo had garnered a reputation for hawkish foreign policy instincts and extreme loyalty to the president.
His state department has now been dragged into the storm. House Democrats leading the impeachment inquiry have subpoenaed the state department for a broad range of documents linked to their lines of inquiry over Ukraine.
Mr Pompeo was among the administration officials who listened in on the July 25 phone call between Mr Trump and Mr Zelensky.
Trump’s personal lawyer
As Mr Trump’s personal lawyer, the former mayor of New York has taken a central role in the drama.
The whistleblower complaint describes him as the emissary for the US president in his dealings with Ukraine, circumventing the traditional diplomatic channels of the state department and White House.
Rudy Giuliani has since claimed that he only spoke directly with the Ukrainians at the behest of the state department.
He was criticised this year for misrepresenting the findings of Mr Mueller’s Russia investigation when he said the final report cleared the president of wrongdoing. Mr Mueller himself accused William Barr of creating “public confusion” about the findings of the probe.
Since the Ukraine scandal broke, the White House has come under further pressure following reports that Mr Trump had asked Australian prime minister Scott Morrison to help Mr Barr with a review that Mr Trump hoped would discredit the Mueller investigation.
The Washington Post reported that Mr Barr met foreign intelligence officials from the UK, Australia and Italy to gather material for his inquiry.
Chairman of the House intelligence committee
As head of the intelligence committee, Adam Schiff will take on a pivotal role in the impeachment investigation as Democrats in the House of Representatives look to use their control of important committees to hold Mr Trump to account.
Mr Schiff has already played an important part in moving the whistleblower’s complaint into the public domain and led the questioning of Joseph Maguire, acting director of national intelligence, on Capitol Hill.
Speaker of the House of Representatives
As the top Democrat in the House, Nancy Pelosi announced that the House would launch an impeachment inquiry into Mr Trump. The announcement followed revelations about Mr Trump’s request that Ukraine investigate the Bidens.
The inquiry marked a big shift in Ms Pelosi’s political calculus. She had previously argued that there was no public appetite for an impeachment inquiry and feared that an inconclusive process would weaken the Democrats ahead of the 2020 election.
When she announced she would launch the impeachment proceedings, Ms Pelosi said the actions of the president had “seriously violated the constitution” and that Mr Trump should be held accountable. “No one is above the law,” she said.
President of Ukraine
The former comedian has had to strike a tricky balance in his relations with Mr Trump, whose support as leader of the world’s most powerful country is crucial to fending off aggression from Ukraine’s neighbour, Russia.
As the transcript of the July call released reveals, the US president asked Mr Zelensky to investigate Mr Biden’s activities in Ukraine while he served as US vice-president in Barack Obama’s administration. Hunter, Mr Biden’s son, held a board seat at Ukrainian natural gas company Burisma, which has since been investigated for corruption.
In his first face-to-face meeting with Mr Trump at the UN, Mr Zelensky said “nobody pushed me” to investigate the Bidens, to which Mr Trump interjected: “In other words, no pressure.”
Ukraine’s prosecutor-general, 2015-16
He is a central figure in Mr Trump’s claims of wrongdoing by Mr Biden, his potential rival in next year’s presidential election.
Mr Trump and his associates claim Mr Biden threatened to withhold $1bn in financing to Ukraine while he was vice-president to force the ousting of Viktor Shokin. Mr Trump’s supporters claim this was because Mr Shokin was investigating Burisma, the Ukrainian gas company where Mr Biden’s son held a lucrative board position. Mr Biden has claimed he wanted Mr Shokin fired because he was stonewalling corruption probes.
Mr Shokin has repeated his claims that the Bidens pushed him out in an interview and affidavit. The Bidens have denied wrongdoing.
Ukraine’s prosecutor-general, 2016-19
He discussed the Bidens’ activities in Ukraine and alleged wrongdoing with Mr Giuliani on several occasions. Yury Lutsenko was removed from office by Mr Zelensky on the grounds that the prosecutor had allegedly ignored corruption cases.
Mr Lutsenko claims to have told Mr Giuliani that Hunter Biden did not violate Ukrainian law while on the board of Burisma, but that Kyiv was ready to co-operate with a US investigation should a request be made.
He had previously settled a tax arrears case relating to Burisma on terms critics claim were favourable to the company. Other cases against Burisma are still being probed by Kyiv’s anti-corruption bureau.
US ambassador to Ukraine, 2016-19
Marie Yovanovitch, who has testified before a congressional committee as part of the impeachment inquiry, had irked Ukraine’s leadership while she was US ambassador for supporting activists and criticising officials for their lacklustre anti-corruption efforts.
She was recalled to Washington several months before her mission was meant to end. Mr Giuliani accused her of supporting anti-Trump Ukrainian activists and other political forces. In the White House transcript of the July call, Mr Trump said she was “bad news and the people she was dealing with in the Ukraine were bad news . . .[We] will get to the bottom of it”.
US special envoy on the Ukraine crisis, 2017-19
The former envoy to Nato was at the centre of negotiations between Ukraine and Moscow to end a five-year proxy separatist war in Ukraine’s Far Eastern regions.
Kurt Volker was well respected in Kyiv, not least for his sharp criticism of the Kremlin during the years that Mr Trump pursued a close relationship with his Russian counterpart Vladimir Putin.
Mr Volker resigned days after the White House phone call transcript with Mr Zelensky was made public. He did not give a reason for his departure.
Mr Giuliani has claimed he engaged with the Ukrainian president’s adviser at Mr Volker’s behest — an unusual request, if true, given that the president’s personal lawyer was not a government official and would not normally be involved in foreign policy.
US ambassador to the EU
Gordon Sondland has long been a Republican donor, but wasn’t always a Trump supporter. The Seattle-born hotel magnate sought to distance himself from the then-presidential candidate during the 2016 election over anti-Muslim rhetoric.
After Mr Trump won in November, however, he donated $1m to the president’s inauguration fund through four limited liability companies. A year later, Mr Trump nominated Mr Sondland for the post of US ambassador to the EU.
Many witnesses to the impeachment inquiry have described Mr Sondland as central to Mr Trump’s efforts to get Mr Zelensky to open investigations into the Bidens and the 2016 US presidential election. Mr Sondland testified in a closed-door deposition in October.
US chargé d’affaires for Ukraine
A career diplomat and military veteran, William Taylor previously served as ambassador to Ukraine from 2006 to 2009. He returned this year at the request of the secretary of state after Ms Yovanovitch was recalled to Washington.
Mr Taylor’s testimony to the impeachment inquiry was hailed by Democrats as a breakthrough. They believe he drew a direct line between a “quid pro quo” expected by Mr Trump and his associates and their dealings with Ukraine’s president. The White House and Republicans have dismissed this.
Former US national security adviser
John Bolton has been a longstanding and controversial figure in senior government roles since the administration of Ronald Reagan. Well known for his hawkish views on North Korea and Iran, Mr Bolton has been a strong advocate of US unilateralism and pre-emptive warfare.
Mr Trump said he fired Mr Bolton in September — though Mr Bolton has said he offered his resignation — allegedly after the two disagreed over Mr Trump’s determination to host talks with the Taliban and the Afghan government at Camp David, the presidential retreat.
According to testimony given to the impeachment inquiry from other White House officials, Mr Bolton was also at loggerheads with the president over his two-track foreign policy in Ukraine which Mr Bolton allegedly characterised as a “drug deal”. He has been asked to appear before the House inquiry, setting the stage for potentially pivotal testimony.
Launching the impeachment inquiry
Rudy Giuliani goes on Fox News television and accuses former US vice-president Joe Biden of pushing for the dismissal of a Ukrainian prosecutor who was investigating a company linked to his son Hunter
The Trump administration recalls Marie Yovanovitch, the US ambassador to Ukraine, several months ahead of schedule
Appearing on US television network ABC, Donald Trump says he would accept information on a political rival from a foreign government
The Washington Post reports that Mr Trump instructed acting White House chief of staff Mick Mulvaney to hold back almost $400m in military aid to Ukraine at least a week before the July 25 call, despite that money being approved by Congress
A recently released transcript reveals that Mr Trump asked Ukraine’s president for a “favour” during a phone call. Mr Trump wanted Volodymyr Zelensky to look to investigate the business dealings of Hunter Biden
According to a whistleblower, White House officials were told to move the transcript of the call into an electronic safe usually used for classified information
Gordon Sondland, US ambassador to the EU, and America’s Ukraine envoy Kurt Volker allegedly advise Mr Zelensky on how to navigate Mr Trump’s requests
Mr Giuliani meets one of Mr Zelensky’s top aides in Madrid to encourage the Ukrainian government to investigate Hunter Biden
The intelligence community inspector general informs Congress of the existence of a whistleblower complaint. Three House committees — foreign affairs, intelligence and oversight — begin an investigation into whether Mr Trump had used his position for political gain
The White House releases military aid to Ukraine
Mr Trump admits he did speak about corruption allegations against Mr Biden in a phone call with Mr Zelensky
Nancy Pelosi announces the launch of an impeachment inquiry
The White House issues a letter refusing to co-operate with the House investigation, claiming it is invalid. House Democrats persist in issuing subpoenas. While some administration staff have heeded the White House order, other employees have decided to comply and appear before the inquiry.
Further reading: The Russia and Ukraine experts who have quit Trump, many of whom have been called to give evidence.
After a month of depositions and evidence-gathering, the House votes to hold public hearings. The measure passes with support from all but two Democrats. Republicans oppose it nearly unanimously. The move will allow the House to build a body of public evidence that will be critical if it eventually votes on formal articles of impeachment.
Design by Kari-Ruth Pedersen. Produced by Adrienne Klasa in London
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