When broadcast journalism moved away from radio, Agronsky returned to NBC, covering the news as well as interviewing prominent figures, including Martin Luther King Jr. as a young man.

At the end of 1962, he recorded a documentary aboard the submarine USS George Washington which received an award at the Venice Film Festival.

[8][14] He left the newspaper in 1937[15] – he was uncomfortable working for Agron, calling it "pure nepotism",[16] as he "wanted to make it on his own" – and moved to Paris[17][16] to open a bookstore,[15] before becoming a freelance journalist covering the Spanish Civil War.

[8] During his time in Europe, primarily Britain and France,[18] he freelanced for various newspapers and translated French stories into English for the International News Service;[19][16] he notably wrote an in-depth piece for Foreign Affairs magazine on the rise of anti-Semitism in Mussolini's Italy.

[16] At the outbreak of World War II, he moved to Geneva in Switzerland, where he met Max Jordan, the National Broadcasting Company (NBC) bureau chief in Europe, who initially asked Agronsky to work freelance writing radio stories.

[16] Despite having no broadcast journalism training, in April 1940 he was hired by NBC as a radio war correspondent when the company expanded their coverage.

[19][16] Jordan wanted to put together an NBC presence throughout Europe to cover the British conflict with Germany in the Balkans and tapped Agronsky to be the bureau chief there.

Joining NBC as their Balkan correspondent, Agronsky became accredited by the British military and Royal Air Force (RAF).

[16] He covered the war from all over the Balkans and much of Eastern Europe before opening a permanent NBC bureau in Ankara, the capital of neutral Turkey.

[citation needed] Though NBC's European war coverage was not particularly celebrated, Agronsky "was a bright spot [...] distinguishing himself under fire in the Balkans, North Africa, and the Middle East.

[22] After Pearl Harbor and Singapore were bombed by Japan on December 7–8, 1941, Agronsky, now considered a seasoned war correspondent, was sent to the Pacific theater.

He was then attached to MacArthur's troops and primarily covered Japan's conquest and the Allied retreat in Asia,[25][8][26] nearly being captured by Japanese soldiers in Kuala Lumpur and riding with the Dutch military on a Lockheed Lodestar for the final leg to Australia.

While many reporters gave milquetoast coverage of McCarthyism, said to be out of fear, Agronsky, like CBS's Edward R. Murrow after him, was openly critical of McCarthy and of the senators who enabled him.

[41] ABC then became the only major network to broadcast the 1954 Army–McCarthy hearings on television, growing their prominence[42] and "sinking McCarthy" due to the public exposure to his excesses.

One of few shows to cover the reports, Agronsky's program nevertheless "ended on a favorable note after conferences [with Hill & Knowlton]", the public relations firm hired by Big Tobacco.

[47] In 1956, with television now the leading broadcast medium, Agronsky left ABC (whose program was still weak) and returned to NBC, as a news correspondent.

[52][53][54] Also speaking on God, an answer Kennedy gave to Agronsky on his faith – that he would "uphold the Constitution" above all – became a prolific quote he used throughout his presidential campaign.

[58] There was much media attention given to the trial, but typically on the wider implications, with little focus on the case of Eichmann: Agronsky's updates, including a verdict interview on the Today show, were atypical in their regularity.

[NBC 5] Upon his return, he gave audiences his opinions on US foreign policy based on what he had witnessed, saying in such a global political climate, no country could remain a bystander, encouraging the general population to not be apathetic.

[63] In the four-day aftermath of the assassination of president John F. Kennedy, Agronsky was one of the senior journalists to lead the large television news coverage.

[66] Sociologists from Columbia University, led by Herbert Gans, interviewed a selection of the on-air journalists covering the assassination shortly afterwards to assess its affects; many were questioned about showing emotion.

[66] Historian William Manchester wrote that shortly after the shooting, Agronsky telephoned Ted Kennedy to ask if he would be flying from D.C. to Dallas, one of limited communications Ted Kennedy received in the aftermath of his brother's assassination due to telephone lines overloading as people tried to call others to talk about the news.

He noted that he had also covered the funeral of Franklin D. Roosevelt, describing the different mood by explaining that people mourning Kennedy seemed moved by his unfulfilled potential.

[68] On November 27, 1963, five days after the assassination, Agronsky conducted an interview with Texas governor John Connally from his bedside in Parkland Memorial Hospital.

Connally's office chose Agronsky to be their reporter; he was found in Arlington National Cemetery late the night before and took a midnight flight to Dallas.

[16] In the 1970s and 80s, Agronsky also moderated a radio show, European Perspectives, tackling international news with foreign correspondents based in Washington on the panel.

Its regular panelists included Hugh Sidey of Time magazine, Peter Lisagor of the Chicago Daily News, and columnists Carl Rowan, James J. Kilpatrick, Elizabeth Drew, and George Will.

It had been at the forefront of the changing face of journalism in format and in terms of personalities, particularly the rise of "buckraking", with its panelists becoming national figures and often sought-after as public speakers in later years.

[81] Evening Edition aired nightly and was on before, during and after the Watergate break-in hearings broadcast on PBS that led, ultimately, to Nixon's resignation on August 9, 1974.

[77] He also interviewed Muhammad Ali and George F. Kennan, a recording of which is held in the American Archive of Public Broadcasting's Peabody Awards collection.