This image went around the world 75 years ago this week. British Prime Minister Winston Churchill, US President Franklin D. Roosevelt and Soviet Josef Stalin sat resolutely at each other's shoulders in the Crimean resort of Yalta. Cocooned in their coats, armor of their own against the winter chill, they look earnestly at the camera.

The scene was supposed to show the unity between the three great Allied powers. And it seemed to offer a glimpse of a lasting peace after the Second World War, unleashed by Nazi Germany.

The Soviets hosted the one-week Yalta Conference on the Crimean peninsula at Livadia Palace, starting on February 4, 1945. The "Big Three" met to talk in the latter stages of the war in Europe. The "thousand-year Reich" that Adolf Hitler had so pompously promised was weeks from oblivion.

Read more:  Auschwitz, 75 years later: A race against time

Pincers closing on Berlin

By February, US and British troops were nearing the River Rhine in the west, while the Red Army was pushing towards the River Oder in the east, little more than 100 kilometers (62 miles) from Berlin. Hitler would make his troops fight until the capital was soaked in blood, eventually committing suicide in his bunker on April 30, with Germany's formal capitulation following barely a week later.

The Big Three met at the Soviets' invitation at the resort city where Russian tsars and the aristocracy used to spend their holidays. They would negotiate rough outlines for a new global peace, as well as the division and de-nazification of Germany. United by a common enemy in recent years, three very different leaders would lay the groundwork for the United Nations — but also fail to maintain their alliance in victory.

"Churchill and Roosevelt corresponded and met regularly during the war. They had only met Stalin once at this point, in Tehran at the end of 1943. They were working under the impression that cooperation would continue for years or even decades after the war, and so they were willing to compromise," historian Jost Dülffer, emeritus professor at the University of Cologne, told DW.

Read more:  A German Battle of the Bulge survivor's last offensive in the Ardennes

Stalin held (and largely kept) the territory

They would negotiate and barter for over a week, each winning concessions of their own. Churchill secured a role for France in the division and occupation of Germany immediately after the war, alongside the three countries represented in Yalta. Roosevelt secured Soviet pledges to join both the New York-based United Nations and the battle against Japan, once the war in Europe ended.

Host Stalin, meanwhile, ensured that the bulk of the territory his Red Army was reclaiming would stay in the Soviet sphere of influence in peacetime. Stalin also secured territorial concessions in the far east at China and Japan's expense, not to mention a veto at the future UN for the USSR.

Officially, the contentious question of Poland's postwar borders was ducked by all three until such time as Germany capitulated. But Stalin stuck to the eastern demarcation line where his troops had stopped in 1939, back when the Soviets and Nazi Germany — uneasy allies at this stage, before Hitler would turn on the Communists — carved up their mutual neighbor in secret.

Historian Dülffer believes all three of the participants achieved some of their goals. "Stalin asserted himself on the tricky territorial questions, while the western powers could plant the seeds for an international framework for peace," he says.

All three satisfied, but no lasting peace

At that stage, according to historian Wilfried Loth at the University of Essen, it still wasn't clear how quickly the alliance would disintegrate and give way to the Cold War.

"At the end of the conference, all three explicitly said: 'Yes, this is a good result — and one we can build on.' In other words, they left Yalta just as optimistic as when they arrived," Loth says. Yet he also acknowledges that all sides had to make a series of compromises to leave the Crimea satisfied.

"In reality, a lasting peace was in no way secured by the Yalta Conference," Loth believes, who adds that the Big Three couldn't completely smooth the waters at their third gathering in Potsdam in July, after Hitler's capitulation. The seeds were being sown for the Cold War to break out even before Churchill's defeat at the ballot box and Roosevelt's death later in 1945.

But what was the Yalta Conference's signature achievement — what endured? Besides convincing the Soviets to join the United Nations, historian Loth points to the joint recognition that all the allies should take a share of responsibility in postwar Germany.

"The talks on the postwar future took place at the highest level and showed that the top dogs were able to find compromises and build trust, if they sat with each other," Loth says, adding that this pattern has held during a series of crises over the years. "Whenever top-level diplomacy fails, there have been problems. You can attribute the flare-up of the Cold War in part to a swift loss of the trust formed at the highest levels, because no more effort was put into fostering it."

Dülffer also thinks that a modern-day Yalta might not go amiss, one that would seek to rekindle 1945's rather bold belief "that we really can build a new peaceful world order together."

"That feeling still thrived in Yalta after the horrors of World War II. Perhaps we need it again today," he says.

Read more:  Opinion: The forgotten lessons of D-Day