In both cases, there is a risk that the cross-party consensus that has supported Ukraine since 2014 against Russia will be broken when the Kremlin annexes the Crimean region of Ukraine and stirs up the war in eastern Ukraine. If Ukraine is associated with one or the other US political party, it could jeopardize relations with its main security patron.
"It is a diplomatic disaster for our relations with the United States," said Alyona Getmanchuk, director of the New Europe Center, a Kiev-based foreign policy think-tank. "I do not know how that story could turn out."
The situation could worsen on Wednesday, when Trump sits down for the first time with Ukrainian President Volodymyr Zelensky on the sidelines of The United Nations General Assembly in New York.
Zelensky has been seeking the meeting for months to demonstrate US support for a country that is still waging war in its east and enduring the annexation of Crimea by Russia. Trump was reluctant and squeezed Zelensky over Biden in a telephone conversation that was the subject of an extraordinary intelligence whistleblower complaint.
Foreign Minister Vadym Prystaiko denied this in an interview with Hromadske, a Ukrainian television channel broadcast on Saturday, as Trump had put Zelensky under pressure during the telephone conversation.
"I know what the conversation was about, and I think there was no pressure," he said. "There was talk, talks are different, leaders have the right to discuss existing problems. This conversation was long, friendly and touched many questions, including those that required serious answers. "
Diplomats, politicians and analysts inside and outside Ukraine said on Saturday that Ukraine was in a precarious position.
"Really could not get worse" for Kiev, said a senior European diplomat on the condition of anonymity, to avoid worsening the situation.
"I'm afraid to do even more harm to Ukraine," said one a sociable former political leader and declined to comment.
1; who until recently was a comedian with no political experience – will have to act cautiously, a misstep could further fuel the situation in Washington and Ukraine's relations with the Republican
Since Trump embraced Russian President Vladimir Putin and questioned both NATO and the reasons for Ukraine's support, cross-party support for the country in Congress is the most important US security guarantee for Kyiv. If this were undermined, d he occupies a particularly dangerous position in Ukraine.
"Our key interest is to secure, protect and strengthen Ukraine's non-partisan support," said Danylo Lubkivsky, a former Ukrainian Deputy Foreign Minister. "This is not just about Ukraine. Do not trouble Ukraine with internal problems and problems, while Ukraine is fighting Russia's aggression and fighting for its independence and freedom.
Trump's freeze on Ukrainian aid is attracting new attention as he pushes Biden's investigation.
Zelensky also talks about meetings with Putin and with the leaders of France and Germany in the coming weeks to try to find a solution to the conflict that is taking place in the fifth year. The turmoil in Washington is particularly disturbing because it weakens Ukraine's bargaining position.
Zelensky was more open to Russia than his predecessor and negotiated an important prisoner exchange with the Kremlin, suggesting talks with Putin.
The ultimate beneficiary of this whole story is Russia, "said Daria Kaleniuk, executive director of the Anti-Corruption Action Center, a clean-governance organization in Kiev.
Some Ukrainians already fear that Zelensky has offered too much to Trump's team.
"Just stay away. It is not our story. There is nothing to gain, there is a lot to lose, "said Victoria Voytsitska, a former Ukrainian legislator, who took office in 2014 in a wave of Western-oriented activists who had entered politics after the political upheavals of the year.
An investigation "as an instrument to assert that we reopen this to give advantage and leverage to a given candidate would be a mistake".
The Ukrainian policymakers and analysts fear that their leader will ambush with Trump on Wednesday. They fear that this could reverse the efforts made since the 2014 revolution to improve the rule of law, which overthrew a deeply corrupt leader.
An irony is that since its independence from the Soviet Union in 1991, US funds flowed to Ukraine to try Getmantschuk said, to promote an independent judiciary that could withstand the political pressure – exactly the kind of pressure that Trump now exercises.
Surrendering would be a disregard for all Americans, the funds and investments of US taxpayers have given it 28 years for reforms, "she said.
Days after the phone conversation between Trump and Zelensky in July, Trump's personal lawyer Rudolph W. Giuliani held a face-to-face meeting in Madrid with Andriy Yermak, one of Zelensky's best consultants. Said Giuliani. Giuliani said that he had met with Yermak to propose two investigative questions and that Yermak had pointed out that the Ukrainians were ready to continue the investigation. Yermak did not respond to a request for comment.
How Trump and Giuliani pressured Ukraine to investigate the President's rivals.
The first case concerned allegations that the Ukrainian government had worked with Democrats in 2016 to try to derail Trump's presidential bid] During the presidential campaign of 2016, the publication of a ledger in which millions of dollars in payments were made by the former Ukrainian Government to Paul Manafort, Manafort became the campaign chairman of Trump. Manafort was an advisor to Ukrainian President Viktor Yanukovich, the pro-Russia leader who had to resign in 2014.
Giuliani said that the publication of this information was part of a coordinated campaign by the Ukrainian government in support of the Democrats. He did not submit any evidence.
Serhiy Leshchenko, the Ukrainian legislator who unveiled the ledger, released the information to try to combat corruption in Ukraine, and did not intervene in US policy of the Ukrainian gas magnate Hunter Biden in the Board of Burisma appointed.
In 2016, then Vice President Biden demanded the overthrow of Ukraine's top prosecutor, Prosecutor General Viktor Shokin.
Trump and Giuliani have accused the elder Biden of pressing for Shokin's release to protect Hunter Biden from Burisma's investigation.
However, it is unclear how seriously Shokin Burisma persecuted himself at the time he was expelled. Diplomats said at the time that Shokin's fall is related to Western concerns about corruption in Ukrainian justice. Washington's concerns were largely shared by Ukraine's European partners and they welcomed Shokin's departure.
"Fake News Media and its partner, the Democrat Party, want to distance themselves as much as possible from Joe Biden's demand that the Ukrainian government fire a prosecutor who has investigated his son," Trump wrote Saturday on twitter.
Biden said Saturday he had never spoken to his son about his business in Ukraine and accused Trump of "doing so because he knows I'm going to beat him up like a drum. "
Trump urged the Ukrainian leader to investigate Biden's son, and told the persons familiar with the matter.
Trump defended the call with the Ukrainian president, calling him "perfectly orderly and routine" increase in gas production. Then his son got a job at a Ukrainian gas company.
Today's Coverage from Correspondents Around the World
How to Keep Washington Post World Up to Date on Facebook and Foreign News