By February 1945, it was increasingly clear that not only would Adolf Hitler's Third Reich fail to last a millennium as he had hoped; it wouldn’t even survive the spring.

With the end of World War II finally in sight, the “Big Three” Allied leaders—U.S. President Franklin D. Roosevelt, British Prime Minister Winston Churchill and Soviet Premier Joseph Stalin—met in the Soviet resort town of Yalta to plan for the dawn of the post-war world. Although Roosevelt had been the one to propose this follow-up to the Allies’ 1943 Tehran Conference, to project a united front against Nazi Germany, Stalin could dictate the summit’s location on the Black Sea coast because his forces had a stronger battlefield position. While American and British forces had yet to even cross the Rhine River, the Red Army stood some 40 miles from Berlin.

“This is Stalin’s show,” says Robert Citino, senior historian at the National World War II Museum. “He has a giant army occupying most of Central and Eastern Europe, and the Western allies are back on their heels with the Battle of the Bulge and grinding fights on their hands.”

Each leader came to Yalta with the goal of preventing another global war—but they differed on tactics. The frail Roosevelt made the 6,000-mile journey to Yalta by air and sea, zigzagging across the Atlantic to avoid German U-boats, to gain support for his United Nations proposal. Stalin sought to divide Germany to make it incapable of launching another war and to use Eastern Europe as a buffer zone for additional protection. He also wanted punitive reparations from Germany—a measure adamantly opposed by Churchill, who pegged self-determination in Poland as “the most urgent reason for the Yalta Conference.”

READ MORE: Yalta Conference

Once the summer playpen of the czars, Yalta still bore deep scars from the Nazi occupation of the Crimean Peninsula when the Allied leaders arrived. “If we had spent 10 years on research, we could not have found a worse place in the world than Yalta,” quipped a less-than-enthused Churchill, who dubbed the location “the Riviera of Hades.”

The conference opened on February 4, 1945, inside the Livadia Palace, once the summer home of Czar Nicholas II. For eight days, the Allied leaders and their top military and diplomatic staff negotiated amid a haze of cigar and cigarette smoke while feasting on caviar and imbibing vodka and other liquors. “The P.M. seems well,” wrote British diplomat Alexander Cadogan, “though drinking buckets of...champagne, which would undermine the health of any normal man.”

Not all was so opulent inside the palace, though. Sleeping nine to a room, the Americans sprayed DDT to ward off the army of bedbugs. And facing only a handful of functioning toilets, Stalin was among those enduring long lines for bathrooms and buckets. “Excepting only the war, the bathrooms were the most generally discussed subject at the Crimean conference,” recalled U.S. General Laurence Kuter.

By the time the summit concluded, the trio had agreed to demand Germany’s unconditional surrender and the division of the country—and the capital of Berlin—into four occupied zones administered by American, British, French and Soviet forces. They settled on the payment of German reparations “to the greatest extent possible,” with the amount to be determined later. With Roosevelt’s advisors warning him that an invasion of Japan could claim one million American lives, and the atomic bomb still untested, the president gained Stalin’s secret pledge to attack Japan within three months after Germany’s surrender in return for diplomatic recognition of its satellite state of Mongolia and the restoration of territories lost in the 1905 Russo-Japanese War. Stalin also agreed to the formation of the United Nations after the Soviet Union received veto power in the Security Council.

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The greatest debate in Yalta came over the fate of Eastern Europe. The conference shifted Poland’s borders westward, with the Soviet Union annexing much of the country’s east with land seized from northeast Germany granted as compensation. The agreement also contained loose language for the inclusion of democratic leaders from a Polish government-in-exile, backed by the British and Americans, in the provisional communist-dominated government installed by the Soviets. It also called for free democratic elections in Soviet-occupied countries in Eastern Europe.

With the Red Army far outnumbering the Allies on the western front, Stalin had the upper hand in dictating the terms of the agreement. “It was not a question of what we would let the Russians do, but what we could get the Russians to do,” said American delegate and future secretary of state James Byrnes.

One thing not subject to debate at Yalta was Roosevelt’s health. Although the youngest of the three, the president cast a gaunt, ghostly figure with sallow cheeks and sunken eyes. “Everyone seemed to agree that the president had gone to bits physically,” wrote Churchill’s physician.

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By the time of Roosevelt’s death two months later on April 12, it was becoming clear that Stalin had no intention to support political freedom in Poland. World War II had begun with the invasion of Poland’. It ended with Poland under Soviet domination. Poland was not among the dozens of countries represented when the conference to form the United Nations met for the first time in San Francisco on April 25.

Two days after the United States dropped the atomic bomb on Hiroshima, the Soviet Union declared war on Japan. A week later, Japan surrendered. The Yalta Conference had helped to end World War II. But it now began to shape the ensuing Cold War. No longer bound by a common enemy, the uneasy alliance of capitalist and communist superpowers would not endure. “An iron curtain is drawn down upon their front,” Churchill wrote about the Soviets to Roosevelt’s successor, Harry Truman, on May 12, 1945.

In February 1946, American diplomat George Kennan wrote his “long telegram” to Byrnes in which he urged the abandonment of thoughts of cooperation with the Soviets and the adoption of a policy of “containment” to prevent the spread of communism. The principle would become the bedrock of American foreign policy toward the Soviet Union for decades to come.

The rise of the Cold War, revelations of Yalta’s secret agreements and the development of the atomic bomb that reduced the need for Soviet intervention in the Pacific Theater led to criticism that Churchill and Roosevelt, hampered by his weakened state, yielded too much to Stalin. “You can’t say Yalta was a sellout unless you come up with a strategy to evict Stalin from Eastern Europe,” Citino says. “Look at a map in February 1945 and see where the contending armies are, and it’s obvious why Stalin was able to turn Eastern Europe into a satellite state. I’m not sure the fighting fit and energetic Roosevelt of 1933 would have gotten a better deal out of Stalin at Yalta.”

Watch full episodes of World War II: Race to Victory.