President Trump on Sunday essentially admitted to inviting Ukrainian officials to interfere in the 2020 U.S. election. Trump acknowledged that in a July 25 phone call with Ukraine’s new president, Volodymyr Zelensky, he urged him to launch an investigation into Democratic presidential candidate and former Vice President Joe Biden. Democrats argue that this is an impeachable offense; Trump supporters claim that it is Biden who is guilty of inappropriate behavior. Meanwhile, Ukraine and its new president are caught unenviably in the middle.

The American public may have started paying attention only recently amid reports that a whistleblower complained about the content of phone conversations Trump had with a foreign leader, possibly more than one head of state. But Ukraine and its new president have been victims for several months of a relentless pressure campaign from the President’s personal attorney, Rudy Giuliani.

I warned on these pages two weeks ago that Trump was holding Ukraine hostage to his own political interests. The situation has only gotten worse.

Giuliani has sought to turn the Russia collusion narrative on its head, arguing that it was Ukrainian collusion with the Clinton campaign, not Russian collusion with the Trump campaign, that should be investigated both in Kyiv and Washington. Giuliani cites a former Ukrainian parliamentary deputy’s exposure of payments made to former Trump campaign manager Paul Manafort as proof of such interference. That deputy, Serhiy Leshchenko, refuted Giuliani’s charges in an op-ed Sunday in the Post.

Giuliani also has accused Biden of inappropriately interfering in a Ukrainian investigation into a controversial energy company with which Biden’s son, Hunter, was connected. Biden played a key role during the Obama Administration in supporting Ukraine after the Euro-Maidan revolution in 2014. The Obama Administration was right to press for the dismissal of then-Ukrainian prosecutor general Viktor Shokin, as I, from my think tank perch at the time, and other supporters of Ukraine were urging in 2016, too. Shokin was an obstacle to fighting corruption.

Giuliani’s allegation, furthermore, has a major flaw: Shokin’s successor, Yuri Lutsenko, acknowledged having no evidence to support any wrongdoing by Biden or his son.

And yet no matter how unfounded Giuliani’s charges might be, Biden the candidate will emerge politically damaged from this. Hunter Biden indeed showed terrible judgment in associating himself with Burisma, the controversial energy company, in a country where his father was actively engaged—a view shared by a number of Obama Administration officials. That is now coming back to haunt his father, even though neither did anything illegal. Politics, alas, is a brutal sport.

At the same time, Giuliani seems unconcerned with the damage he is doing to Ukraine and its relationship with the United States. His smear campaign has badly damaged the image of Ukraine as he tars it as a helplessly corrupt country. In reality, Ukraine has a huge corruption problem, but it is anything but helpless. Millions of Ukrainians gave Zelensky a huge mandate in presidential and parliamentary elections earlier this year. And Zelensky won by promising to launch major reforms in battling corruption. Instead of focusing on this worthy goal, Ukraine’s new leadership is dealing with an unwelcome and unnecessary crisis in U.S.-Ukraine relations.

Making matters worse, Zelensky badly needs military support in fending off ongoing Russian aggression, with more than 13,000 people killed as a result of Putin’s invasion and illegal annexation of Crimea and close to 2 million Ukrainians displaced in the fighting. And yet Trump held up the latest tranche of military assistance, in what may have been an attempt to leverage Ukraine to launch an investigation. Under Congressional and public pressure (thanks especially to a Washington Post editorial), the military aid finally was released.

Ukraine cannot afford to lose—or even appear to be losing—the backing of the United States. Zelensky also needs international help in tackling the problem of corruption. Controversial oligarch Ihor Kolomoisky, who owned the station on which former comedian Zelesnky’s hit show appeared, returned to Ukraine after the election and recently met with the new leader, asserting his own importance in decision-making for Ukraine. Zelensky, by all appearances a capable and agile politician, needs positive reinforcement from the West to push back against Kolomoisky’s efforts to reestablish himself as a power behind the throne.

After promising an Oval Office invitation to Zelensky and being one of the first to congratulate him on his electoral victory, Trump apparently has held that meeting hostage to Ukrainian acquiescence to his and Giuliani’s demands. Their meeting this week in New York on the margins of the UN General Assembly is a serious downgrade from a visit to the White House.

Recent stories in the Washington Post and the New York Times likely alarmed those in Kyiv. First, the Post:

A former senior administration official who repeatedly discussed the issue with Trump said that the president thought “what we were doing in Ukraine was pointless and just aggravating the Russians.”

“The president’s position basically is, we should recognize the fact that the Russians should be our friends, and who cares about the Ukrainians?” said the official.

Then this in the Times:

Privately, Mr. Trump has had harsh words about Ukraine…“They’re terrible people,” he said of Ukrainian politicians, according to people familiar with the meeting. “They’re all corrupt and they tried to take me down.”

One person who must be smiling at all this is Russian President Vladimir Putin. Unlike the Russian collusion story, where Putin and his acolytes played an active role in interfering in the 2016 election, Putin does not appear to have played a direct role in this new scandal—at least so far. With declining support at home, Putin could not ask for a better gift than to see U.S.-Ukraine relations deteriorate and Zelensky on the ropes.

Congress has a responsibility to get to the bottom of this scandal immediately, no matter where it leads regarding President Trump. It also must reassure Ukraine that the United States stands steadfastly with Ukraine at this critical juncture so that Putin does not infer from Giuliani’s and Trump’s words and deeds that it is open season on his neighbor.