Wartime conferences exposed cracks in the US–Soviet alliance

How Stalin, Roosevelt, and Churchill shaped the postwar world

The Yalta Conference was a pivotal 1945 meeting between Allied leaders that helped shape the postwar global order and laid the groundwork for the founding of the United Nations.

The Cold War (1947-1991) prompted the birth of NATO and the Soviet Warsaw Pact

The geopolitical rivalry between the United States and Soviet Union was considered “cold" because the two countries never directly engaged in military combat during the time period. This page from the Kennedy Presidential Library outlines the causes and major events of the early Cold War.

US–Soviet hostility began long before the Cold War

US–Soviet tensions began decades before WWII. After the 1917 revolution, the US refused to recognize the Bolshevik regime and even sent troops to fight against it.

NATO was formed in 1949 to deter Soviet expansion, prevent European militarism, and encourage political integration.

Churchill’s 1946 ‘Iron Curtain’ speech warned of growing Soviet domination

In a 1946 speech, Winston Churchill declared that an “Iron Curtain” had descended across Europe—dividing East from West. The address marked one of the first public acknowledgments of the emerging Cold War and coined the term that would define the conflict.

Cold War rivalries fueled fierce competition in international sports

From Olympic medal counts to hockey showdowns, the US and USSR used sports to showcase ideological superiority. Athletic victories were framed as proof that each system—capitalist or communist—produced stronger, more disciplined citizens.

Propaganda became a key weapon in the US–Soviet Cold War

Both superpowers waged a global battle for hearts and minds through propaganda—using film, radio, art and education to promote their values. The US emphasized freedom and prosperity, while the USSR championed socialism and anti-imperialism.

How two US Presidents defined WWII and its aftermath

The National WWII Museum’s “To the Best of My Ability” podcast series delves into how Presidents Franklin D. Roosevelt and Harry S. Truman steered the US through World War Two.

During the Cold War, the rules-based order was largely limited to the West

The Soviet Union and its allies operated outside the Bretton Woods institutions, meaning the postwar liberal order functioned as a regional rather than a truly global system. This changed with the USSR's collapse in 1991.

Tensions between the US and European NATO allies

The Associated Press article discusses US Defense Secretary Pete Hegseth's assertion in February of 2025 that restoring Ukraine's prewar borders or NATO membership for the country are both unrealistic. This represented a large rift between the United States and its other NATO allies, prompting concern about America’s commitment to the future of the alliance.

The US and the USSR backed opposing sides in dozens of proxy wars during the Cold War

To avoid direct confrontation, the superpowers supported rival factions in conflicts around the world—including in Korea, Vietnam, Angola, and Afghanistan.

The Kennan Telegram shaped early US Cold War strategy

In 1946, diplomat George Kennan sent a long telegram from Moscow warning that the Soviet Union was inherently expansionist. His analysis laid the groundwork for the US policy of containment that defined the early Cold War.

The formation of the UN elevated the US on the world stage

This podcast episode of "To the Best of My Ability" from the National WWII Museum goes behind the scenes of the United Nations' founding from the American perspective. It explores how FDR's vision for global peace took shape, how Truman carried it forward, and how Eleanor Roosevelt helped define human rights—set against the backdrop of wartime diplomacy, Cold War tensions, and the San Francisco Conference, where the UN Charter was signed.

Soviet control spread across Eastern Europe after WWII

In the late 1940s, the USSR solidified control over Eastern Europe by installing pro-communist regimes in countries like Poland, Hungary and Romania—often through rigged elections and political repression.

European leaders pursued appeasement of Hitler in the 1930s, hoping to avoid war.

How failures at Versailles Conference led to more racial inequality

Suffering a pandemic and the aftermath of a war that killed 50 million, the world in 1920 faced a turning point as it negotiated a new political order. As today, the key issue was racial inequality.

The 1941 Atlantic Charter was a World War II alliance and model for the UN

The Atlantic Charter was a pivotal 1941 agreement between Franklin D. Roosevelt and Winston Churchill, outlining shared goals for a post-World War II world rooted in freedom and self-determination. These ideals later inspired the founding principles of the United Nations.

See an animated map of the entire Cold War.

The Soviet Union’s surprising first atomic test ended the US nuclear monopoly

In 1949, the USSR successfully tested its first atomic bomb—ending the US monopoly on nuclear weapons and sparking an arms race that would define the Cold War.

The US and the USSR each boycotted Olympic Games during the Cold War

The US led a boycott of the 1980 Moscow Olympics over the Soviet invasion of Afghanistan. In retaliation, the USSR and its allies skipped the 1984 Los Angeles Games.

The failures of the interwar period made the case for a new international system

After World War I, countries devalued their currencies, raised tariffs to block imports, and seized territory unchecked, with the international community unable to organize effectively to stop them. The result was a global depression and, eventually, another world war.

The Nazis and Soviets agreed to a non‑aggression pact in 1939

On August 23, 1939, Nazi Germany and the Soviet Union signed the Molotov–Ribbentrop Pact—a public commitment to not attack each other combined with a secret agreement dividing Eastern Europe into spheres of influence. This pact enabled Germany to invade Poland unopposed from the east and delayed conflict with the USSR until June 1941.

Questions about the US' commitment to its allies may have sparked a new nuclear age

Some US allies—from Warsaw to Seoul—are reevaluating their security amid doubts over American nuclear commitment, signaling the possibility they may want to acquire their own weapons.

The Truman Doctrine marked the start of US containment strategy

Introduced in 1947, the Truman Doctrine pledged US support for nations resisting communism—starting with Greece and Turkey—and launched the containment policy that defined early Cold War strategy.

The Concert of Europe's collapse contributed to World War I

The 19th-century great power system gradually unraveled due to rising nationalism, imperial rivalry, and shifting alliances—leading to its collapse in 1914 and the outbreak of the deadliest war the world had yet seen.

Before World War II, the US was a Pacific power

Decades before Pearl Harbor, the US held major Pacific territories—Hawaii, the Philippines, Guam, American Samoa, and numerous island bases—giving it strategic reach across the western Pacific. This presence increasingly overlapped with Japan’s imperial ambitions in the region, contributing to rising tensions.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

The Marshall Plan aimed to rebuild Europe and limit Soviet influence

Launched in 1948, the Marshall Plan provided over $12B (roughly $150B today) in US aid to help rebuild Western Europe. While framed as economic recovery, it also served as a Cold War tool—tying countries to the US and excluding the Soviet bloc.

Since World War II, formal declarations of war and peace treaties have become increasingly rare, replaced by cease-fires, authorizations of force, and "special military operations."

Post-WWII decolonization in Africa led to Cold War proxy conflicts

As newly independent African nations emerged after World War II, the US and USSR vied for influence—backing opposing sides in civil wars and revolutions. Conflicts in Angola, Ethiopia and Mozambique became proxy fronts in the Cold War.

The Concert of Europe was an earlier attempt to manage great power relations through shared rules

After the Napoleonic wars, European powers established a system of regular consultation to manage conflicts and maintain the balance of power. It offered relative stability for nearly a century before deteriorating.

Hitler declared war on the United States four days after Pearl Harbor

Despite having no treaty obligation to join Japan’s fight, Hitler declared war on the US on Dec. 11, 1941. The move pulled America into the European theater and is widely seen as one of Hitler’s most strategic blunders.

During the Cold War and into the 21st century, US and Soviet/Russian leaders repeatedly agreed to arms control treaties, though strained tensions have led to the expiration of agreements in recent years.

Before Pearl Harbor, the US was a nonbelligerent ally to the Allied powers

Between September 1940 and December 7, 1941, the United States remained officially neutral—yet President Roosevelt incrementally shifted policy from “cash‑and‑carry” to Lend‑Lease, funneling critical military aid to Britain and other allies without entering the war.

World War I causes

World War I was, as the name says, truly war on the global scale. Fought between the French, Russian, British, Austria-Hungary, Ottoman, and Russian Empires, it was in part, a battle for territory. And after the war ended, several of these empires collapsed. Explore the different causes of World War II in this article.

Stalingrad was the turning point of WWII in Eastern Europe

The six-month siege (July 1942–February 1943) ended when the Soviet Union’s counteroffensive, Operation Uranus, encircled and destroyed Germany’s 6th Army. This decisive victory shifted momentum permanently to the Soviets on the Eastern Front, marking a major strategic reversal in Europe and undermining Nazi Germany’s war capacity.

Japan's imperial expansion in Asia in the 1930s set the stage for war with the US.

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'Cold War Conversations' podcast shares voices from the conflict's frontlines

This award-winning podcast features gripping interviews with the people who lived through the Cold War—spies, soldiers, defectors, and civilians. Covering everything from the Berlin Wall to nuclear standoffs, it offers unfiltered, emotional accounts of Cold War life and conflict.

The 1955 Warsaw Pact was the Soviet Union’s answer to NATO

The pact included Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, Romania, and the USSR. The pact established collective security and a joint military command between the member countries.

The failed Bay of Pigs invasion led to the Cuban Missile Crisis, which brought the world to the brink of nuclear annihilation

Moscow's decision to deploy nuclear missiles in Cuba—just 90 miles from the US—pushed the world to the brink of nuclear war. To prevent future crises, both sides later set up a direct hotline and boosted arms-control diplomacy

The world rapidly decolonized after World War II, with roughly a hundred new countries emerging between 1945 and 1989.

Decolonization isn't complete, as nearly 2 million people were living in UN-designated non-self-governing territories as of 2023.

The world is shifting from unipolarity toward a multipolar order

The post-Cold War world was briefly unipolar after 1991, with the US standing alone as a global superpower following decades of US-Soviet bipolarity. Analysts increasingly describe today's order as multipolar, with China, Russia, the US, and regional powers all competing for influence.

A 1983 NATO war simulation provoked the Soviets to prepare for war

The "SNAFU" podcast, hosted by actor and comedian Ed Helms, explores some of the biggest blunders in history. Season one focuses on the 1983 NATO Able Archer military exercise, a war game that simulated nuclear attacks on the Soviet Union. The USSR mistook the exercise for a genuine threat and prepared its forces for war. Helms recounts this almost catastrophic event in world history with his signature humor.

The 1956 Suez crisis was one of the earliest tests of the rules-based order

When Britain, France, and Israel secretly invaded Egypt, the Eisenhower administration supported UN resolutions condemning the invasion and called for a ceasefire—publicly criticizing its closest allies to uphold the principle that force should not be used to resolve international disputes.

The global nuclear arms regime has slowly eroded over the past few decades

Both Russia and the United States have withdrawn from key Cold War-era arms-control pacts. Russia's 2022 invasion of Ukraine marked a turning point, as it suspended its participation in inspections and data-sharing agreements.

The Berlin Wall physically separated East and West Berlin for nearly three decades, preventing East Germans from fleeing to the West and earning the nickname 'the Iron Curtain.'

The treaty that ended the First World War laid the groundwork for the Second.

Franklin D. Roosevelt's 1941 speech framed World War II as a global fight for universal rights

Eleven months before the attack on Pearl Harbor, President Roosevelt outlined four fundamental freedoms that, in his words, people "everywhere in the world" ought to enjoy—speech, worship, freedom from want, and freedom from fear.

Cold War nuclear tests exposed thousands to atomic blasts

After World War II, nuclear powers conducted thousands of weapons tests. This video pairs archival footage with interviews of veterans who witnessed Pacific test explosions, capturing the scale, shock, and human experience of being near a nuclear detonation.

Watch the historic treaty signing that established NATO in 1949

NATO was created with the signing of the North Atlantic Treaty on April 4, 1949, in Washington, DC. The clip embedded in the webpage includes a newsreel with an excerpt from US President Harry Truman’s speech celebrating the historic day.