Ideological Foundations of the Cold War

This collection focuses on the ideals that formed the basis of American policy toward the Soviet Union during the early years of the Cold War. The collection includes 57 documents totaling 681 pages covering the years 1945 through 1952. Supporting materials include photographs, oral history transcripts, biographies and a chronology of events. Related collections available from the Truman Library include subject guides on the Berlin AirliftKorean WarMarshall PlanTruman Doctrine and United Nations.

Composite Image. Stalin, Truman and Churchill at Potsdam over NSC 68.


Displaying 1 - 49 of 49 documents








After meeting Josef Stalin at the Potsdam conference in July 1945, President Harry S. Truman wrote in his diary: "I can deal with Stalin. He is honest-but smart as hell." Not a year later tempers flared on all sides as Stalin spoke about the ultimate collapse of capitalism and President Truman instructed his Secretary of State James Byrnes to stop "babying the Soviets." Diplomacy between the two countries quickly degenerated into mutual distrust, military and nuclear buildup, and cold war. This state of cold war would span nine presidencies and nearly fifty years.

While ideology cannot entirely explain the origins of the cold war, it may help explain why the cold war became so enduring and contentious. Both nations held dramatically different worldviews, nurtured by their domestic values. The Soviet Union envisioned a world-wide global revolution leading to a Communist utopia. The United States believed in democracy and private enterprise. As their World War II coalition melted away in the face of growing political disagreements, the rhetoric of both nations turned shriller and argumentative, making faith in negotiations and treaties virtually non-existent.

In February of 1946, George Kennan, the chargé d'affaires in the American Embassy in Moscow and an expert on Russia, wired the longest telegram in State Department history. The "long telegram," as it became known, expressed doubt about the possibility of direct, armed conflict with the Soviet Union. Kennan believed the greater Soviet threat arose from its support of Communist parties and other subversive elements worldwide. He argued that the strategy to deal with this threat should be to strengthen Western institutions and an American commitment to assist endangered nations. One month later in the small town of Fulton, Missouri, former British Prime Minister Winston S. Churchill spoke of an "iron curtain" having descended across Eastern Europe, creating a "Soviet sphere" of influence just as Kennan warned against.

In July 1946, President Truman asked Clark Clifford, his special counsel, to prepare a report concerning U.S. relations with the Soviet Union. Written with the assistance of George Elsey, a junior naval aide, Clifford's report discussed agreements observed or broken by the Soviet Union and Soviet foreign policy and its effect on the United States. The report also underscored Moscow's determination to expand its military power and obtain the atomic bomb. In direct contrast to Kennan's long telegram, the report stressed the importance of expanding military readiness to deal with the increasing Soviet military threat.

In 1947, Kennan wrote an article for the journal Foreign Affairs entitled "The Sources of Soviet Conduct," published under the pseudonym "X". In the article, Kennan restated many of the points made in his long telegram, and first articulated his idea of containment. Kennan believed the West needed to maintain a steady, firm policy to keep the Soviet threat in check and wait for what Kennan believed was inevitable: the downfall of the Soviet Union. This strategy became the inspiration behind U.S. aid to Greece and Turkey, the Marshall Plan, and the creation of the North Atlantic Treaty Organization (NATO).

Two years after Kennan outlined his ideas about containment, the entire nation was shocked by the detonation of the first Soviet atomic bomb in August 1949. President Truman responded by approving development of the hydrogen bomb and ordering a complete review of U.S. national security policy. The result was National Security Council Paper 68 (NSC 68), approved in April 1950 by President Truman. The report rejected Kennan's view that the Soviets were not militarily prepared to attack the West, and argued that in order for containment to be more than a bluff, the United States must be sufficiently prepared for armed conflict. It recommended a massive military buildup and increased foreign aid.

The Cold War raged on through the remainder of the Truman presidency with occasional flare-ups such as the invasion of South Korea and charges of Communist spies in government. Through the accusation of U.S. spying during the Eisenhower administration, the Cuban missile crisis and the construction of the Berlin Wall in the Kennedy administration, and the alternate arms reductions and increases in the Nixon and Reagan administrations, the Cold War remained active well into the 1980s. The Cold War effectively ended with the fall of the Soviet Union in 1991.



  • February 4-11: Yalta Conference - Churchill, Roosevelt and Stalin meet to discuss terms of German surrender, Russia's aid in the war in the Pacific and postwar European conditions.
  • April 12: President Roosevelt dies; Harry S. Truman becomes president.
  • May 7: Nazi Germany unconditionally surrenders.
  • June 5: Division of Germany into four zones of occupation by U. S., Britain, France and Soviet Union.
  • June 26: The United Nations Charter is signed in San Francisco.
  • July 16: First successful atomic bomb (Trinity) is tested at Alamogordo, New Mexico.
  • July 17 - August 2: Potsdam Conference - calls for the unconditional surrender of Japan; military industries are banned in Germany.
  • July 26: Clement Attlee replaces Winston Churchill as British Prime Minister.
  • August 6: Atomic bomb is dropped on Hiroshima.
  • August 8: Stalin declares war on Japan; sends troops to Manchuria.
  • August 9: Second atomic bomb is dropped on Nagasaki.
  • August 14: World War II ends - Japan surrenders unconditionally.
  • August 25: Ho Chi Minh's communists seize control of Hanoi.
  • September 2: Ho Chi Minh proclaims Vietnam's independence from France.
  • September 2: Japanese officials surrender to General Douglas MacArthur aboard the USS Missouri.
  • September 8: Korea - U.S. and Soviets disarm the Japanese; Soviets occupy Korea north of the 38th parallel; U. S. occupies Korea south of the 38th parallel.
  • November 20: The International Military Tribunal - Nazi War Crimes Trials begin in Nuremberg.


  • January 19: United Nations - Iran charges the Soviets with interference in Iranian internal affairs; a confrontation between the U. S. and the Soviet Union appears likely.
  • February 9: Stalin delivers his "Two Camps" Speech declaring communism and capitalism to be incompatible and irreconcilable..
  • February 22: George F. Kennan sends Truman the "Long Telegram" detailing Soviet foreign policy objectives.
  • March 5: Churchill delivers the "Iron Curtain" Speech at Westminster College, Fulton, Missouri.
  • March 10: Truman demands removal of Soviet troops from Iran.
  • May 3: The International Military Tribunal for the Far East - Japanese war crimes trials begin in Tokyo.
  • July 4: Philippines - a U. S. colony since 1902, becomes independent.
  • August 1: Truman signs Atomic Energy Act (McMahon Act) - the Atomic Energy Commission of five civilians will control the research, development, testing and construction of nuclear warheads.
  • December 2: The U.S. and Great Britain agree to "Bizone" - an economic merger of their zones of occupations in Germany; leads to tensions with the Soviets.


  • March 12: Truman Doctrine - the president announces U.S. support for "free peoples who are resisting subjugation by armed minorities or by outside pressures" and asks Congress to approve for $400 million in aid to Greece and Turkey.
  • March 22: Truman signs Executive Order No. 9835 creating the Federal Employees Loyalty and Security Program.
  • June 5: Marshall Plan - Secretary of State George Marshall offers U. S. aid to European countries (including the Soviet Union) to help them recover from World War II.
  • July 1: X Article - Foreign Affairs (Long Telegram) publishes unsigned article that recommends U. S. foreign policy should seek to contain communism.
  • July 26: National Security Act - the CIA, the National Military Establishment (later renamed Department of Defense) and the National Security Council are created.


  • February 25: Soviets take over Czechoslovakia and establish a communist regime.
  • March 17: Brussels Treaty signed - collective defense agreement between Great Britain, France, Belgium, the Netherlands, and Luxemburg.
  • May 14: Israel - The United States recognizes the new nation of Israel.
  • June 7: The U.S., Great Britain, and France recommend the creation of a West German state.
  • June 18: U.S., Britain, and France announce a plan for new currency for the three western zones of Germany and West Berlin; Soviets detail a currency plan of their own for Soviet zone and all of Berlin.
  • June 24: Berlin Blockade - Soviet troops blockade highways and railroads to shut off power to more than two million West Berliners; Truman orders the airlifting (Berlin Airlift) of food, coal and other necessities to the city.
  • July 30: The Big Four meet in Moscow to discuss Berlin.
  • August 3: Whittaker Chambers testifies before the House Un-American Activities Committee (HUAC), naming Alger Hiss as a Soviet spy.
  • August 15: The Republic of Korea (South Korea) is established.
  • September 9: The Democratic People's Republic of Korea (North) is established.
  • October 27: The Voice of America - approved by Congress to broadcast anticommunist radio programs into Iron Curtain countries.
  • November 2: Truman wins the presidency.
  • December 2: The "Pumpkin Papers" - Whitaker Chambers tells of hiding secret State Department documents passed by Alger Hiss inside a hollow pumpkin on his Maryland farm.
  • December 15: Hiss is indicted by a U.S. grand jury on two counts of perjury.


  • January 19: U.S. and British labor unions accuse the World Federation of Trade Unions being a front for the communist party and withdraw.
  • April 4: The North Atlantic Pact - U. S. and eleven other countries pledge mutual defense assistance.
  • May 2: Chiang Kai-shek flees to Formosa (Taiwan).
  • May 5: China and North Korea sign a mutual defense treaty.
  • May 12: The Berlin Blockade ends.
  • June 16: In a press conference, Truman warns against anticommunist hysteria.
  • June 29: South Korea - U. S. occupation forces withdraw.
  • September 21: The German Federal Republic (West Germany) established - Allies give up control of the American, British, and French occupation zones.
  • September 23: Truman announces the Soviet Union has exploded its first atomic bomb.
  • October 1: The People's Republic of China is proclaimed by Mao Zedong.
  • October 6: Mutual Defense Assistance Act of 1949 - signed by President Truman.
  • December 1: Chiang Kai-shek established the Nationalist government on Taiwan; the U. S. will not send troops to protect Taiwan.


  • January 21: Alger Hiss is convicted on two counts of perjury in his second trial.
  • January 31: Truman orders the development of the hydrogen bomb.
  • February 3: Physicist Klaus Fuchs is arrested in London for spying for the Soviet Union; he will admit to spying three days later.
  • February 9: Wisconsin Senator Joseph McCarthy charges that communists have infiltrated the State Department.
  • February 14: Sino-Soviet Pact -The Soviet Union and China reach a mutual defense agreement.
  • April 7: NSC-68 - The National Security Council top secret memo describes a Soviet "design for world domination" and calling for a massive military buildup of both nuclear and conventional weapons.
  • May 8: Vietnam - Truman orders first military advisors and $15 million to aid French in the Indochina.
  • June 25: Korean War - war breaks out when North Korea invades South Korea.
  • June 27: UN Security Council approves military aid to South Korea.
  • June 30: U.S. troops enter the Korean War.
  • July 8: General Douglas MacArthur named UN commander in Korea.
  • July 17: Julius Rosenberg is arrested for spying for the Soviet Union; his wife, Ethel, is arrested for spying on August 11.
  • September 15: Inchon Landing - MacArthur's forces begin the liberation of South Korea.
  • October 1: MacArthur drives North Koreans out of South Korea; American troops pursue North Korean army across the 38th parallel.
  • October 24: American forces approach the Yalu River on the Chinese border.
  • November 1: People's Republic of China enters the Korean War on the side of North Korea.
  • November 25: UN forces are forced to retreat from Yalu River when China enters the Korean War.
  • December 16: Truman declares a state of national emergency exists due to the Korea War.
  • December 19: The NATO appoints General Dwight D. Eisenhower to be the first Supreme Allied Commander Europe.


  • April 11: MacArthur fired - Truman relieved him of his command for openly criticizing the administration's foreign policy.
  • June 21: UN troops push the communist forces out of South Korea.
  • July 10: Truce talks start in Korea.
  • September 8: Japanese Peace Treaty officially signed - The U.S. keeps troops in Japan.
  • October 22: Turkey and Greece join NATO.
  • November 27: Cease-fire line established at 38th parallel in Korea.


  • March 29: Truman announces that he will not seek reelection.
  • October 24: Republican presidential candidate Dwight Eisenhower pledges to go to Korea to seek peace.
  • November 1: The U.S. explodes the first hydrogen bomb at a test site in the Marshall Islands.
  • November 4: Dwight Eisenhower wins the presidential election.


Displaying 1 - 113 of 113 images
58-574 (untitled)

President Harry S. Truman and Joseph Stalin at Potsdam

58-611 (untitled)

Attlee, Truman, and Stalin at Potsdam

62-770 (untitled)

Stalin, Truman, and Churchill at Potsdam

63-1455-69 (untitled)

Stalin, President Truman, and others during the Potsdam Conference

63-1457-21 (untitled)

Last meeting of the Potsdam Conference

62-769 (untitled)

Crowded Meeting Room at The Potsdam Conference

63-1457-29 (untitled)

Winston Churchill, Joseph Stalin, and Harry S. Truman Shaking Hands at the Potsdam Conference

59-1106 (untitled)

Harry Truman and Winston Churchill in Jefferson City, Missouri, en route to Fulton

58-1 (untitled)

Churchill, Truman, and Stalin at Potsdam