He began his career with the New York Herald Tribune and fast established a substantial reputation as a journalist, particularly by his comprehensive reportage of the Bruno Hauptmann trial in 1934.

Two years later, the North American Newspaper Alliance (NANA) contracted Alsop and Robert E. Kintner to write a nationally syndicated column on a daily basis.

In 1941, after it had become clear that the United States would soon enter World War II, Alsop and Kintner suspended their column and volunteered for the armed forces.

Unable to secure passage out of the city, Alsop was eventually taken into custody as an enemy alien and interned at Hong Kong by the Imperial Japanese Army.

After six months, he was repatriated through a prisoner exchange as a journalist, but he had really been a combatant, a fact he managed to conceal by changing into civilian clothes and with the help of friends.

After the war, Alsop resumed his journalism career, now working with his brother Stewart to produce a thrice-weekly piece, called "Matter of Fact", for the Herald Tribune.

Alsop attended the Los Angeles Democratic Convention in July 1960, where along with Phil Graham he convinced JFK to appoint Lyndon B. Johnson as his running mate.

[citation needed] Joseph Alsop was a vocal supporter of America's involvement in the Vietnam War, and in his column, he strongly advocated for escalation.

"[12] His insider access to the Washington elite granted him plenty of confidential information, revealed mostly at the dinner parties of the "Georgetown Set.

He wanted to provoke the president into action as he warned about the impact a defeat would have on American credibility, attacked Johnson's manhood by accusing him of weakness and compared him to Kennedy.

Even as the popularity of his column declined and he lost close friendships, Alsop's hawkish attitude remained unwavering until the end of the Vietnam War.

It has been described as "brimming with revelations about Alsop's sex life on several continents," including a report that one of his lovers was Arthur H. Vandenberg Jr., who had resigned as Dwight Eisenhower's appointments secretary in 1953.

[26] His accounts, delivered to a friend in the CIA, quickly reached the FBI, allowing J. Edgar Hoover to spread the information through the Eisenhower administration, many of whose members had fought sharp battles with Alsop.

Alsop told White House Press Secretary Bill Moyers that he believed the administration was tapping his phone and was spreading gossip about his personal life, all in an attempt to stop leaks.

[32] Alsop's life was dramatized in David Auburn's play The Columnist, which ran on Broadway from April 25 to July 8, 2012, and focused on the interplay of his politics, his journalism, and his sexuality.