Eighty years ago this week, American troops liberated Dachau concentration camp just north of Munich. German forces in Northern Italy surrendered. And Hitler dictated and signed his last will and testament in the bunker. Yet although the Third Reich was collapsing on every front, the end of this war, which had killed millions of human beings, still depended on the life of just one man.

The Allies had made a fundamental mistake when they believed after the bomb plot of July 1944 that an army which had tried to kill its own commander-in-chief must be in a state of collapse. What they could not grasp was that the failure to kill Hitler meant that he, the SS, Gestapo and Nazi Party would force everyone to fight on until his death. It was once again the problem of democratic confirmation bias, which prevents us from properly understanding the mentality of dictators and their entourage.

The Allies, or more specifically the Americans, made a similar mistake understanding Stalin. Roosevelt, with the arrogance of his great charm, thought he could make Stalin a friend. Eisenhower also thought that he could win Stalin’s trust by passing on his plans for the western Allies’ advance across Germany. Both were misled in return.

On 8 March, Stalin had heard from General Susloparov, his liaison officer with Eisenhower’s headquarters, that the Americans were across the Rhine at Remagen. The Allies also had a plan in place for an airborne drop on Berlin, Operation Eclipse, in the event of a sudden Nazi collapse. Stalin instantly summoned Zhukov back to Moscow to start planning what was to be known as the ‘Berlin Operation’. This would consist of three Fronts, or Army Groups, attacking across the rivers Oder and Neisse. Zhukov’s First Belorussian Front in the middle would attack from its bridgeheads across the Oder straight towards Berlin. Marshal Konev’s First Ukrainian Front would cross the River Neisse to the south, and then, in the north, Marshal Rokossovsky’s Second Belorussian Front, having cleared Pomerania, would attack around Stettin.

Stalin, knowing that the British wanted to head for Berlin, made sure that Eisenhower was misinformed as to Soviet intentions. But Eisenhower, without warning his British allies or even his British deputy, Air Marshal Tedder, informed Moscow of his own plans in a notorious signal, SCAF 252. He told Stalin that ‘Berlin was no longer a particularly important objective’. He wanted to push through central Germany and further towards the south, having heard of Nazi plans for a last-ditch defence in an Alpenfestung (alpine fortress) around the Bavarian-Austrian border.

Churchill was horrified. He feared that the Americans were too keen to placate Stalin and over-cautious about friendly fire incidents. American pilots had just shot down six Soviet fighters over the Oder east of Berlin, thinking they were German. The Soviets were furious. Stalin was also enraged by the American refusal to include the Soviet Union in the secret discussions about an armistice in northern Italy. He still suspected that the western allies might come to a separate peace agreement with Berlin at the last moment.

The rapid surrender of German forces in the West increased his paranoia. It did not occur to him that the Germans were bound to resist the Red Army more desperately, having heard of its atrocities and acts of revenge. Soviet propaganda demanded why the Red Army had to fight bitterly for every village, while the Allies rolled forward with ease in the west ‘conquering with cameras’, as Ilya Ehrenburg wrote. Patton’s Third Army was heading for Prague, where the Czechs had risen in revolt, supported by Vlassov’s army of Russian renegades turning against their German allies at the last moment, a desperate act which would still not spare them from Soviet vengeance.

Stalin’s recurrent nightmare was that the Americans might re-arm the Wehrmacht and attack the Soviet Union. This was not entirely far-fetched; soon after the surrender in May, Churchill, horrified by the brutal Soviet suppression of Poland, asked his chiefs of staff to contemplate Operation Unthinkable, which included re-arming Wehrmacht units and pushing back the Red Army. The chiefs returned to say that it was indeed unthinkable: the Americans would never agree, nor would British troops, whose morale had been boosted by pro-Soviet newsreels lauding the sacrifices of their allies. Disastrously, a premature signal was sent to Montgomery to gather up Wehrmacht weaponry in case it was needed. Some think that the spy John Cairncross may have heard of this and passed it on to Moscow.

Stalin, unlike Eisenhower, saw Berlin as vital. It was, of course, the great symbol of Soviet victory over Nazi Germany, but it offered another prize. Pro-Soviet spies within the Manhattan project had warned him that the Americans were close to creating an atomic weapon. On his orders, Operation Borodino was accelerated, but the Soviet Union lacked sufficient uranium. Stalin ordered Lavrentiy Beria, his chief of secret police, to prepare NKVD rifle units and special detachments to be ready to seize all the uranium, equipment and German nuclear scientists they could find.

While Stalin urged Zhukov to speed his preparations to take Berlin, he encouraged Eisenhower to continue with his plan to head further south. On 31 March he told the US diplomat Averill Harriman in Moscow that the ‘Germans’ last stand would probably be in the mountains of western Czechoslovakia and Bavaria. The very next morning, Stalin held his famous meeting with Marshals Zhukov and Konev to decide on the final details for the Berlin operation. Stalin emphasised the vital importance of taking the capital before the Allies. He then signalled Eisenhower later that day, 1 April, to agree that ‘Berlin has lost its former strategic importance’, and to say that the Soviet command would send only second-rate troops against it. He also lied shamelessly over the date of the attack, saying it would take place in the second half of May. It was the greatest April Fool in modern history. Even when the offensive on the Oder began on 16 April, with a bombardment of nearly two million shells in a single day, Stalin told the Americans that only reconnaissance forces were being sent towards Berlin.

He was already alarmed by the rapidity of the American advance. On 12 April, four days before his own Berlin Operation began, the Americans had crossed the Elbe south of Dessau. Their divisional commanders estimated that they could reach Berlin within 48 hours. All the SS units were on the Eastern Front and the troops of Wenck’s 12th Army consisted mainly of barely-trained youngsters who had no tanks or anti-tank weapons. The chief of staff of the 12th Army and the chief operations officer, both of whom I interviewed, said that they would not have been able to resist for even a day.

Even so, Eisenhower and General Omar Bradley were reluctant to attack. Bradley thought that taking Berlin would cost them 100,000 casualties, an estimate which he later admitted to be far too high. And what, he asked, would be the point of taking territory at a heavy cost which they would later have to hand back to the Soviets under the European Advisory Commission agreement over Occupation Zones? The trouble was that the Allies had no idea of conditions and attitudes within Germany. Apart from the SS, most units were prepared to surrender rapidly to the western Allies, in fact those around Berlin were longing for the Americans to arrive before the Russians. As the current Berliner joke went ‘optimists were learning English and pessimists were learning Russian’.

General William Hood Simpson, the commander of the Ninth Army, on the other hand, had no doubt that he could break through to Berlin in no time. By the morning of 15 April, he had built up sufficient forces in his bridgehead for a breakout. His men were longing to go, but that morning he was summoned to Army Group headquarters by Bradley and told that Eisenhower had decided to halt on the Elbe. A dejected Simpson returned to his own headquarters wondering how he was to break the news to his men.

This brings us to an obvious counterfactual question. What would have happened if the American Ninth Army had gone flat out for Berlin on, say, 16 April, the same day that Zhukov and Konev launched their attacks on the Oder and the Neisse?  My instinct is that they would have indeed advanced rapidly, probably to the outskirts of Berlin and even into Dahlem. None of the SS formations could have been pulled out of the line east of the city while fighting the First Belorussian Front and the First Ukrainian Front. On the other hand, the American advance would surely have been spotted by Soviet aviation, and my guess is that Stalin would have immediately ordered his air forces to attack them, pretending that they believed them to be German reinforcements. He would then have accused the Americans of criminal adventurism and blamed them for the misunderstanding. Eisenhower, desperate to avoid inter-Allied casualties, would have pulled his forces back immediately.

Stalin’s plan for the Berlin Operation was not to go straight for the city. It was to encircle it first, with Zhukov’s armies swinging round from the east to the north, while Konev’s forces came up from the south to seal off the western side. All this was to prevent the Americans getting there first and to make sure that Beria’s NKVD secured the uranium. The Soviets, however, did not know that the Germans had sent most of their uranium down to Haigerloch in the Black Forest, or even that the Americans had already secured a stockpile near the Elbe, which was later used in the atomic bomb dropped on Japan.

So, back to Hitler in the bunker. As I discovered in the RGVA Special Archive in Moscow, Hitler had just heard of the lynching of Mussolini, hanged from a petrol station gantry by Italian partisans. The details were typed out for him in the special outsize Führerschrift on gold-headed writing paper. His visceral fear was being captured by the Russians and taken back to Moscow in an iron cage.

Hitler was in a violent mood. Following on from Göring’s betrayal down in the south, he had heard also on the afternoon of 28 April that the faithful Himmler was in touch with the western Allies through the Swedes. That evening he had the SS representative at Führer headquarters, Hermann Fegelein, arrested and executed just before he escaped from Berlin. Fegelein was married to Eva Braun’s sister, and she refused to intervene on his behalf. Hitler then ordered his newly promoted head of the Luftwaffe, Marshal Ritter von Greim, to fly out from the Tiergarten, even though he had a smashed leg. He was to be assisted by the aviatrix Hanna Reitsch. His mission was to fly to Admiral Dönitz in Flensburg to make sure that Himmler was arrested.

Then, in the early hours of this mouvementé night, Hitler married Eva Braun. A nervous Nazi official was brought in from Volkssturm sentry duty to carry out a proper National Socialist marriage ceremony. It included asking both Hitler and his bride, appropriately dressed in black, whether they were of pure Aryan descent and free from hereditary diseases. As they signed the register afterwards, Eva began to write ‘Braun’, then scratched it out. She was now Frau Hitler and insisted on being addressed as such by the servants. Hitler’s hand shook so much that his signature was illegible. In a world of betrayal, Eva Braun had been rewarded for her loyalty unto death, the unspoken clause in their marriage contract.

After the surviving entourage gathered to congratulate the couple and toast them, Hitler took one of his secretaries, Traudl Junge, to another room in the concrete submarine to dictate his personal will and public testament. The formerly admiring Junge was dejected to hear nothing but the same stream of clichés and recriminations that the Jews had started the war, a typical case of dictators confusing cause and effect.

Although accepting his own death ‘at the head of his troops’ in Berlin as imminent, Hitler proceeded to appoint a fantasy Nazi replacement government with loyalists – Dönitz, Goebbels and Martin Bormann – in the key positions. Meanwhile, the very subdued wedding party underground was accompanied by an orgy upstairs, as Traudl Junge discovered, when she went in search of food for the famished Goebbels children ignored in their bunk beds by their parents. ‘An erotic fever seemed to have taken possession of everybody,’ she wrote. ‘Everywhere, even on the dentist’s chair, I saw bodies locked in lascivious embraces.’ The SS officers of the escort had been tempting impressionable young women back to the Reich Chancellery with promises of parties and champagne and food. It also seemed to offer an impression of comparative safety as the news spread of the mass rapes by the Red Army in the suburbs and even closer in.

Nobody could escape the atmosphere of a Nazi Götterdämmerung in the capital, where Hitler insisted on staying. Albert Speer agreed with him, at their very last meeting in the bunker, that the Fall of Berchtesgaden did not have quite the same dramatic quality as the Fall of Berlin, with monuments crashing down.

Yet Speer, when interrogated by American interrogators some days after the end of the war, made a bitter observation. ‘History always emphasises terminal events,’ he complained at that moment. Speer hated the idea that what he saw as the early achievements of Hitler’s regime would be obscured by its final, grotesque collapse. He simply refused to recognise that nothing reveals more about the true nature of a dictatorship than the manner of its downfall. This is why the subject of National Socialism’s final defeat is so fascinating – and also so important.

History is seldom tidy. Normally there are overlaps and unfinished business stretching from one era to another. But suddenly, 80 years after the end of the Second World War, which established through the United Nations an international order of respect for national sovereignty and borders, we face a guillotine moment which cuts us off completely from that past. On 24 February of this year, Western nations were shocked when the United States voted with Russia and refused to condemn its aggression and war crimes against Ukraine. The Trump administration even supported Putin’s propaganda against Zelensky and Ukraine.

The Second World War was a war like no other, and yet it has come to define the very idea of war itself. Politicians and the mass media alike still cannot resist the temptation to dramatise the importance of a particular crisis by making often misleading comparisons. The paradoxes in our attitudes to the subject are striking. The conflict brought world history together for the first time, partly because of its global reach, but also because it accelerated the end of colonialism in Africa, the Middle East and South and East Asia. And yet despite its overwhelmingly international character, every country involved created and then tended to cling to its own national narrative.

Many cannot agree when the Second World War began. Each country has its own historical version of events because experiences and memories of it are so different. For Americans, the war started in December 1941 with the Japanese attack on Pearl Harbor and Hitler’s declaration of war on the United States a few days later. Vladimir Putin, meanwhile, insists that it began only in June 1941 when Hitler invaded the Soviet Union. He angrily tries to whitewash Stalin’s own invasion of Poland in September 1939 under the secret protocols of the Nazi-Soviet Pact.

There are many superficial parallels between the present and the Second World War – from the betrayal of the Czechs in the Munich agreement to both Hitler and Putin’s deliberate confusion of cause and effect on the reasons for the war they started. I would, of course, not go as far as equating Roosevelt and Eisenhower’s appeasement of Stalin to President Trump acting like Putin’s ‘useful idiot’, but the unpredictability of the whole situation today makes it feel as if we are rudderless in a whirlpool.

I would like to end with former presidential advisor Fiona Hill’s account of Trump and Putin’s conversation at the G-20 conference in Osaka in 2019. Putin, to please Trump, at one point said how much he had been doing secretly to help Israel. Trump immediately boasted: ‘Nobody’s done as much as me to help Israel.’

Putin, putting on a straight face, said: ‘Perhaps they should rename the country after you.’

Trump, after considering this suggestion quite seriously, replied: ‘No, I think that would be going a little too far.’ Such narcissism is truly beyond parody.