KIEV, Ukraine – It’s often said that Donald Trump’s opinion is swayed by the last thing he’s heard, and it changes again when he hears something else. So Sergei Markov’s version of what Vladimir Putin will tell Trump about Ukraine on Monday is worth considering closely.

Markov, a longtime pro-Kremlin political analyst and advisor to top Russian officials, told me when I reached him by telephone that he was sitting on an embankment in annexed Crimea overlooking the Black Sea, and then sketched out his sense of the Putin agenda for the summit in Helsinki.

“Putin is going to tell Trump the real story about what America has been doing in Ukraine, the story that Trump does not know,” Markov said. “American military advisers and officers have been fighting against Russia in Ukraine,” he claimed. “The United States has been funding Nazi groups in Ukraine; we hear reports that we have got a few American prisoners, U.S. officers – that would be useful for weighty arguments,” Markov said.

None of this is confirmed independently – or at all – but facts are much less important than impressions where Trump is concerned. “Putin’s goal is to shock Trump by true facts about this war,” says Markov, “so when the American President goes back, he will put an end to support for Ukraine.”

We’ll see. Trump in the past has been more than willing to consider, even embrace, the Putin rationale for the annexation of Ukrainian Crimea and the war in Donbass, eastern Ukraine. Trump reportedly told other leaders at the G7 summit last month that Crimea is basically Russian because most people speak Russian.

In much the same way, Trump has been inclined to accept Putin’s denial that Russia meddled in the elections that put Trump in the White House.

It seems President Trump likes to toy with such ideas to keep everyone, including his allies, his friends and indeed his closest advisors, off balance.

But in Ukraine the situation is far too serious to be toyed with. The government and the people need desperately to know that Washington is on their side, as they’ve been promised in the past, and they need to know if the United States of Trump will remain a reliable ally.

The just-ended NATO summit was, from Kiev’s point of view, far from encouraging. While official statements of support for Ukraine sounded unequivocal, once Trump floated the idea he might actually pull out of NATO altogether, the observer states like Ukraine and Georgia were left wondering if any American commitment could be trusted, especially after he cancelled or postponed bilateral meetings. Both have had major parts of their territory shorn off by Russia. It does not look they’ll get them back any time soon, and they have to wonder now if Trump will help them keep from losing more.

The meeting Thursday morning that was meant to address this situation, along with the ongoing war in Afghanistan, had to start without Trump, who showed up late. At a subsequent, hastily called press conference, rather than making a firm commitment to see Crimea restored to Ukrainian sovereignty, Trump insisted the problem really was the result of “weakness” by his predecessor, President Barack Obama. Trump mentioned in passing that he had met finally “with Ukraine,” leading to speculation he couldn’t remember the name of President Petro Poroshenko.

For his part, Poroshenko said the meeting went well, and Trump’s commitment to Ukraine’s security and territorial integrity is firm.

But the impression of equivocation left by the Brussels encounters is just the sort of thing that people here in Ukraine’s capital worry about when Trump meets Putin.

Since the early days of Ukraine’s armed conflict with Russia, Washington has been supporting Kiev with advice on reforms, with military training, and business investments.

Many people here remember wistfully that in December 2013 American senators from both the Republican and Democrat parties assured thousands of Ukrainian revolutionaries from a stage in the middle of Kiev’s revolutionary Independence Square, the Maidan, that “the American Senate stands with the people of Ukraine.”

Ukrainians hope that while Trump is staying in his private resort in Scotland this weekend, he might spare the time to learn about events in Ukraine in the winter of 2013-2014, when snipers killed more than 100 people in the heart of this country’s capital; about Russia annexing the Crimean peninsula just a few weeks later, when Ukraine was still crying over its victims; about tragedies caused by the war in Donbass, and children left without their parents, without homes.

A strong public voice behind the ongoing effort to bring pro-European reforms to Ukraine, Yekaterina Sergatskova, says she is very concerned about Trump’s agenda for the summit with the Russian leader. “The United States should demonstrate its respect for Ukrainian citizens, for the choice we have made to embrace democratic reforms,” Sergatskova, the founder of Zaborona (Banned) media told The Daily Beast.

Like most Ukrainian liberals, Sergatskova considers President Putin an aggressor, who made a decision to annex her home, Crimea, and backed pro-Russian militia forces in Donbass. “And the most important thing: I hope, we are not going to see any deals that the leaders have agreed on in advance – our country should finally become an independent state, should not lose its dignity.”

The conflict has killed more than 10,000 people in the last four years. Not only independent public figures but also the country’s leader was concerned about the outcome of Trump’s for face to face meeting with Putin. In a piece for the Financial Times, Ukraine’s President Poroshenko asked President Trump not to do anything on Ukraine without Ukraine: “I wish Mr. Trump well in his efforts to bring Mr. Putin back into line.”

Poroshenko said he believes the U.S. president will honor his promises: “It is important for us that no nasty surprise happens behind our backs and we have received assurance [from the U.S. side] that this is not going to happen.”

A senior presenter on Ukraine’s Priamy TV channel, Yevgeny Kiselyov, did not think that Trump could afford to make deals behind Ukraine’s back, considering that Trump’s ex-campaign manager Paul Manafort was deeply involved in Ukraine’s pre-revolution scams. “Ukraine has strong support in Washington – as far as we can see. Trump understands that any deals with Putin would confirm that special counsel Robert Mueller has every reason to investigate collusion,” Kiselyov said.

In a recent interview here, Ukrainian Member of Parliament Serhiy Leschenko gave an example of the way Washington affects, and even directs, the political winds in Ukraine.

“ The investigation of Paul Manafort’s case was frozen in Ukraine and only after three U.S. senators wrote a letter to Prosecutor General Yuri Lutsenko addressing the issue was the investigation reopened — actually right on the next day after the letter. That is the way it is when Washington interferes with Ukraine’s politics,” Leschenko said.

Do U.S. senators need to get involved in Ukraine’s politics more often, we asked?

“That would be a very banana republic approach but it does not surprise me that the U.S. plays a very important role here,” said Leschenko. “Many times Ukraine has benefitted. When Washington pushed us for anti-corruption reform, for example. But knowing how unpredictable President Trump can be, any decision made in Helsinki might be changed when President Trump comes back to Washington.

On that point, there seems to be very wide agreement indeed.