Dulles was a significant figure in the early Cold War era, who advocated an aggressive stance against communism throughout the world.

Dulles also helped design the Dawes Plan, which sought to stabilize Europe by reducing German war reparations.

During World War II, Dulles was deeply involved in post-war planning with the Federal Council of Churches Commission on a Just and Durable Peace.

Despite having supported his political opponents, Dulles became a special advisor to president Harry S. Truman, with a focus on the Indo-Pacific region.

Throughout his tenure, Dulles favored a strategy of massive retaliation in response to Soviet aggression and concentrated on building and strengthening Cold War alliances, most prominently NATO.

His maternal grandfather, John W. Foster, had been Secretary of State under Benjamin Harrison, and doted on Dulles and his brother Allen, who would later become the director of the Central Intelligence Agency.

At Princeton, Dulles competed on the American Whig-Cliosophic Society debate team and was a member of University Cottage Club.

In Panama, Dulles offered waiver of the tax imposed by the United States on the annual Canal fee, in exchange for a Panamanian declaration of war on Germany.

After the Nazi Party came to power, Dulles expressed sympathies for Adolf Hitler, requiring his legal staff in Berlin to sign "Heil Hitler" on all of Sullivan & Cromwell's outgoing mail; fearful of the optics, Sullivan & Cromwell's junior partners forced Dulles to cut all business ties with Germany in 1935.

[12] He was prominent in the religious peace movement and an isolationist, but the junior partners were led by his brother Allen, so he reluctantly acceded to their wishes.

The event sparked the continuing Fundamentalist–Modernist Controversy in the international Christian Churches over the literal interpretation of Scripture against the newly developed "Historical-Critical" method including recent scientific and archeological discoveries.

[15] During the Second World War, Dulles engaged in Post-War Planning under the auspices of the Federal Council of Churches Commission on a Just and Durable Peace.

[17] In 1945, Dulles participated in the San Francisco Conference as an adviser to Arthur H. Vandenberg and helped draft the preamble to the United Nations Charter.

In the immediate aftermath of the bombings, he drafted a public statement that called for international control of nuclear energy under United Nations auspices.

[19] In the late 1940s, as a general conceptual framework for contending with world communism, Dulles developed the policy known as rollback to serve as the Republican Party's alternative to the Democrats' containment model.

[20] Dewey appointed Dulles to the United States Senate to replace the Democratic incumbent Robert F. Wagner, who had resigned for ill health.

[23] In his role as an external "consultant" to Truman's State Department, Dulles became the key architect of the 1952 San Francisco Peace Treaty which ended the U.S. occupation of Japan, as well as the U.S.-Japan Security Treaty, which ensured that Japan would remain firmly in the U.S. camp in the Cold War and allowed the continuing maintenance of U.S. military bases on Japanese soil.

[27] Dulles was viewed by the press as too favourable to big business,[28] and in Eisenhower's own memoirs as too old to potentially wield significant influence upon the Court.

His tenure as Secretary was marked by conflict with communist governments worldwide, especially the Soviet Union; Dulles strongly opposed communism, calling it "Godless terrorism.

[33] That led directly to the coup d'état via Operation Ajax in support of Mohammad Reza Pahlavi, who regained his position as the Shah of Iran.

"[35] In 1954, at the height of the Battle of Dien Bien Phu, Dulles helped plan and promote Operation Vulture, a proposed B-29 aerial assault on the communist Viet Minh siege positions to relieve the beleaguered French Army.

President Eisenhower made American participation reliant on British support, but Foreign Secretary Sir Anthony Eden was opposed to it and so Vulture was canceled over Dulles's objections.

He subsequently left to avoid direct association with the negotiations; Dulles's exit contributed to the Geneva Conference's failure to resolve the conflict in Vietnam.

[41] Later, at Geneva, Dulles objected to any proposals by China and the Soviet Union for a diplomatic reunification of Korea, thus leaving the Korean conflict unresolved.

[45] Thomas Dudley Cabot, former CEO of United Fruit, held the position of Director of International Security Affairs in the State Department.

Their son Avery Dulles (1918–2008) converted to Roman Catholicism, entered the Jesuit order, and became the first American theologian to be appointed a Cardinal.

In January 1959, Dulles returned to work, but with more pain and declining health underwent abdominal surgery in February at Walter Reed Army Medical Center when the cancer's recurrence became evident.

A central West Berlin road was named John-Foster-Dulles-Allee in 1959 with a ceremony attended by Christian Herter, Dulles's successor as Secretary of State.

[56] Entertainer Carol Burnett rose to prominence in 1957 singing a novelty song, "I Made a Fool of Myself Over John Foster Dulles".