WASHINGTON — It was not a country that would naturally have seemed high on the priority list of a president who came to office relishing a trade clash with China, promising to reorder the Middle East and haranguing European allies to spend more on NATO.

But for US President Donald Trump, Ukraine has been an obsession since the 2016 campaign.

Long before the July 25 call with the new Ukrainian president that helped spur the formal start of impeachment proceedings against him in the House, Mr Trump fretted and fulminated about the former Soviet state, angry over what he sees as Ukraine’s role in the origins of the investigations into Russian influence on his 2016 campaign.

His fixation was only intensified by his hope that he could employ the Ukrainian government to undermine his most prominent potential Democratic rival in 2020, former US vice president Joe Biden.

His personal lawyer, Mr Rudy Giuliani, has undertaken a nearly yearlong, free-ranging effort to unearth information helpful to Mr Trump and harmful to Mr Biden.

And Mr Trump has put the powers of his office behind his agenda: He has dispatched US Vice President Mike Pence and top administration officials with thinly veiled messages about heeding his demands about confronting corruption, which Ukrainian and former American officials say is understood as code for the Bidens and Ukrainians who released damaging information about the Trump campaign in 2016. This summer he froze a package of military assistance to Ukraine even as the country, eager to build closer relations with Washington, continued to be menaced by its aggressive neighbor Russia.

When Ukraine elected its new leader, Mr Volodymyr Zelenskiy, on April 21, Mr Trump seized on the moment as an opportunity to press his case. Within hours of Mr Zelenskiy’s victory, Mr Trump placed a congratulatory call as he was en route from his Mar-a-Lago resort in Florida to Washington.

He urged Mr Zelenskiy to coordinate with Mr Giuliani and to pursue investigations of “corruption,” according to people familiar with the call, the details of which have not previously been reported.

Four days after this first call, Mr Trump said on Sean Hannity’s Fox News program that he “would imagine” that US Attorney General William Barr would like to review information about Ukraine’s actions in the 2016 election.

On Wednesday (Sept 25), the Justice Department said that the official named to review the origins of the counterintelligence investigation into Mr Trump’s campaign, Mr John H. Durham, is looking into the role of Ukraine, among other countries. “While the attorney general has yet to contact Ukraine in connection with this investigation, certain Ukrainians who are not members of the government have volunteered information to Mr. Durham, which he is evaluating,” the Justice Department said in a statement.

Mr Trump’s focus on Ukraine started after a law enforcement organisation, the National Anticorruption Bureau of Ukraine, released damaging information about cash payments earmarked to his campaign chairman, Mr Paul Manafort, by the Russia-aligned political party of Ukraine’s ousted former president.

Even after Mr Manafort stepped down from the Trump campaign under pressure, he insisted to Mr Trump’s aides that Mrs Clinton’s campaign was behind the surfacing of the documents revealing the payments and questioned the authenticity of the documents.

Mr Manafort remained in contact with Mr Trump’s aides through the election. And during the presidential transition, Mr Manafort told people that he was discussing possible investigations with the president-elect’s team into whether Ukrainians tried to undermine the Trump campaign through the release of damaging information about Mr Manafort.

Mr Trump was briefed on the subject and would consider pursuing investigations “if the Democrats keep pushing” investigations into Russian meddling on Trump’s behalf, Mr Manafort told people in the days before the inauguration.

After special counsel Robert Mueller began his investigation of Russian interference in the campaign and possible obstruction of justice by the president, Mr Giuliani stepped in to grant Mr Trump’s wish for an investigation with a different focus, albeit one lacking government authority and operating outside normal foreign policy channels.

With Mr Trump’s blessing, Mr Giuliani has worked for months with current and former Ukrainian prosecutors to seek information and push for investigations into matters that he admitted would be of political benefit to Mr Trump.

One involves the overlap between Mr Biden’s diplomacy in Ukraine as vice president and his son Hunter’s position on the board of a Ukrainian energy company owned by an oligarch who had been accused of corruption.

A second involves the claim that Ukrainian officials sought to damage Mr Manafort and Mr Trump’s campaign in 2016. Mixed in with the issues related to Mr Manafort is the unsubstantiated theory that the hack of Democratic National Committee emails in 2016 could have been carried out by Ukrainians who in turn pinned the blame on Russia — something that Mr Trump brought up in general terms with Mr Zelenskiy on the July 25 call.

Throughout Mr Giuliani’s efforts he would brief Mr Trump, keeping the president abreast of his work. But Mr Giuliani also decided he would talk publicly about what he found.

“I decided because I couldn’t get law enforcement agencies interested in doing their job, I would just put it out publicly and I would see if anyone was interested in it,” Mr Giuliani said in an interview Wednesday.

Mr Giuliani’s work set the stage for the April call, Mr Trump’s first contact with Mr Zelenskiy, a former comedian and political neophyte. Mr Zelenskiy is seen by the West as a reformer elected with a mandate to take a hard line against both Russian aggression and the political corruption that has long plagued his country.

The White House released a summary— but not a full transcript — of the April call, noting that Mr Trump pledged to work with the new administration “to implement reforms that strengthen democracy, increase prosperity and root out corruption.”

Mr Giuliani planned to travel to Kyiv in May to try to meet with Mr Zelenskiy to urge him to pursue the corruption investigations of interest to Mr Trump, telling The Times, which revealed his efforts and the planned trip, that he had the full support of Mr Trump.

Ukrainian officials blocked his efforts to arrange a meeting with Mr Zelenskiy, and Mr Giuliani canceled the trip at the last minute amid a backlash.

Instead, Mr Giuliani said he conveyed his information to an aide to Mr Zelenskiy in a late July phone call, followed by an Aug 1 meeting in Madrid, which was revealed by The New York Times. The meeting was arranged with the knowledge and cooperation of the State Department, and Mr Giuliani said he briefed the department afterward.

As Mr Giuliani was pressing for discussions with Ukrainian officials, the American ambassador to Ukraine was recalled in May, two months before her term was to expire, amid growing attacks from conservatives in the United States who saw her as insufficiently supportive of Trump — an early public sign of US foreign policy being intertwined with Trump’s political priorities.

And even though the Defence Department certified in a letter to Congress in May that Ukraine was making sufficient progress in fighting corruption to justify the release of US$125 million (S$172 million) in military assistance, Mr Trump subsequently froze that aid and more — not releasing it until this month, under pressure from both Republican and Democratic lawmakers. THE NEW YORK TIMES