Last week, en route to Oxford, I dropped in on Boris Johnson at his rural retreat, where he is writing his ‘not exactly memoirs’. Unlike Cincinnatus, he has no plough, but he does possess one of those squat, computer-driven lawnmowers which move silently about the lawn, grazing. Boris is impulsive. At lunch, he suddenly said: ‘Let’s play tennis.’ So we did. At another point, he said: ‘Why don’t you come to Ukraine on Friday?’ So I thought I would. The journey involved 24 hours of train against 19 hours in Kyiv, but there is something romantic about reaching a foreign country by train. Besides, Ukrainian trains are more efficient than British ones even though (or because?) there’s a war on.

The formal purpose was a conference about how the West can maintain Ukraine’s fight against Russia two years in, but before that, we were shown round Babyn Yar. There, in September 1941, Nazis murdered nearly 34,000 people, overwhelmingly Jews. Babyn Yar means Woman’s Ravine. After the massacres, the ravine was filled up to hide the bodies. Many further murders were committed there and similarly hidden. When the Germans fled in 1943, they exhumed the bodies and burnt them, to destroy the evidence. This terrible place provokes so many thoughts, but the one most relevant to Ukraine’s current struggles relates to ‘the crime of oblivion’. To a westerner, it seems incomprehensible that Soviet Russia, having driven the Nazis out, did not wish fully to commemorate the victims of their enemies. In 1976, a monument was at last erected, but the Soviet authorities were so morbidly afraid of anything religious or which celebrated minorities that they never allowed any visible recognition that most of the dead were Jews. In Vladimir Putin’s mind, this Soviet impulse mingles with his Russian imperialist one: for him, Ukraine does not exist, except as a geographical expression. Today, the Victor Pinchuk Foundation, organisers of the conference, have redeemed much of the site, erecting an astonishing wooden synagogue which opens out, by mechanical means, like a giant book to show a brightly painted canopy in which the disposition of the constellations that first murderous night in September 1941 is reproduced as flowers on a deep blue background. We were honoured to be shown this operation. There used to be a daily Jewish service there. It is grimly fitting that, since the invasion, it has had to stop. Babyn Yar has also been bombed.

In the conference hall, Boris encouraged Ukrainian will to win and European and American desires to help. I was struck that those who share such views are putting their Brexit antagonisms to one side. People like Aleksander Kwasniewski, ex-president of Poland, and Carl Bildt, ex-prime minister of Sweden, amiably shared a platform with Boris. For his part, Boris favours Ukrainian EU entry: if you were in Ukraine’s plight, you would want it too. The most visceral speakers were Ukrainians. Oleksiy Danilov, the national security chief, succinctly exposed why appeasement does not work: ‘If you’re scared of a dog, it will bite you.’ There was a striking intervention by a slender, crop-haired woman who combined combat fatigues with punk rings through her nose. (This style, half fierce patriot, half right-on feminist, is a characteristic Ukrainian phenomenon, by the way.) She apologised for speaking poorly but she had recently been concussed in an explosion at the front and found loud noises and bright lights tricky. In her view, Ukraine has now learnt so much about war that ‘We should be training Nato troops, not the other way round’. I fear she is right.

There is no concealing rising (though still minority) discontent with Volodymyr Zelensky, the inevitable consequence of nearly five years in office, including two of bloody war. His lightning rod is Andriy Yermak, his chief of staff, whom I met. When we called on President Zelensky, the two sat next to one another so I could see how well built Yermak is for his role, seemingly twice the height and width (not fat, just huge) of his boss. As for Zelensky himself, he has searching eyes, and a mixture of tension and humour in his face. Apparently, he does a daily discipline of yoga to clear his mind. Has a single leader in history ever had to broadcast himself so often to his nation and the world? Leaving him, we crossed the courtyard and decided to enter the cathedral of Santa Sophia, which glowed in the dark. It seemed important to visit the tomb of Yaroslav the Wise, about whom Putin discoursed so misleadingly to Tucker the Idiot.

Despite its tribulations, Kyiv maintains a café life of almost Notting Hill-ish chic. Martin Harris, the outstanding British ambassador, guided us to a glorious traditional but groovy restaurant. I ate roast bees (sic) with a cherry coulis. Mr Harris has literally immersed himself in Ukrainian culture. On Epiphany this year, he joined Ukrainians to celebrate the millennium of the first baptism of Christians which marked the founding of Kievan Rus. In his 6 January tweet, he undresses, sinks beneath the freezing waters of the Dnipro and emerges crossing himself. For so many reasons, that must be a Foreign Office first.

En route to our Polish airport, Boris engrossed himself in Archilochus (c.680-645 bc). A classical professor had sent him his translation of the Greek poet’s well-known verse about leadership. Boris essayed his own translation, loyal, he claimed, to the original trochaics: ‘Not for me some strapping general/ With his drill-ground straddling air/ Nor his silly waxed moustaches/ Nor his teased pomaded hair/ Give me one so small you’d think your/ Knees were roughly by his nose/ Hunched and runty, full of heart and/ Like a cat upon his toes.’ Archilochus famously distinguished the fox, who knows many small things, from the hedgehog, who knows one big thing. I had Boris down as a fox, but over Ukraine, I begin to think he might be a hedgehog.