A member of the Forbes family and of the Democratic Party, he previously represented Massachusetts in the United States Senate from 1985 to 2013 and later served as the first U.S. special presidential envoy for climate from 2021 to 2024.

Kerry testified in the Fulbright Hearings before the Senate Committee on Foreign Relations, where he described the United States government's policy in Vietnam as the cause of war crimes.

In 1972, Kerry entered electoral politics as a Democratic candidate for the United States House of Representatives in Massachusetts's 5th congressional district, losing to Republican Paul W. Cronin in the general election.

[38][39] During his tour on the guided missile frigate USS Gridley, Kerry requested duty in South Vietnam, listing as his first preference a position as the commander of a Fast Patrol Craft (PCF), also known as a "Swift boat".

According to Kerry and the two crewmen who accompanied him that night, Patrick Runyon and William Zaladonis, they surprised a group of Vietnamese men unloading sampans at a river crossing, who began running and failed to obey an order to stop.

Their mission on the Duong Keo River included bringing an underwater demolition team and dozens of South Vietnamese Marines to destroy enemy sampans, structures and bunkers as described in the story The Death Of PCF 43.

[50] On March 13, 1969, on the Bái Háp River, Kerry was in charge of one of five Swift boats that were returning to their base after performing an Operation Sealords mission to transport South Vietnamese troops from the garrison at Cái Nước and MIKE Force advisors for a raid on a Vietcong camp located on the Rach Dong Cung canal.

[51] James Rassmann, a Green Beret advisor who was aboard Kerry's PCF-94, was knocked overboard when, according to witnesses and the documentation of the event, a mine or rocket exploded close to the boat.

[66] According to Nixon Secretary of Defense Melvin Laird, "I didn't approve of what he did, but I understood the protesters quite well", and he declined two requests from the Navy to court martial Reserve Lieutenant Kerry over his antiwar activity.

After Republican Congressman F. Bradford Morse of the neighboring 5th district announced his retirement and then resignation to become Under-Secretary-General for Political and General Assembly Affairs at the United Nations, the couple instead rented an apartment in Lowell, so that Kerry could run to succeed him.

On the eve of the September 19 primary, police found Kerry's younger brother Cameron and campaign field director Thomas J. Vallely, breaking into where the building's telephone lines were located.

[24][72] In the general election, Kerry was initially favored to defeat the Republican candidate, former State Representative Paul W. Cronin, and conservative Democrat Roger P. Durkin, who ran as an Independent.

[24] His campaign called for a national health insurance system, discounted prescription drugs for the unemployed, a jobs program to clean up the Merrimack River and rent controls in Lowell and Lawrence.

[24] After Kerry's 1972 defeat, he and his wife bought a house in the Belvidere section of Lowell, Massachusetts,[76][24] entering a decade which his brother Cameron later called "the years in exile".

[24] While studying, Kerry worked as a talk radio host on WBZ and, in July 1974, was named executive director of Mass Action, a Massachusetts advocacy association.

[100][101] In his victory speech, Kerry asserted that his win meant that the people of Massachusetts "emphatically reject the politics of selfishness and the notion that women must be treated as second-class citizens".

The offer was denounced by the Reagan administration as a "propaganda initiative" designed to influence a House vote on a $14 million Contra aid package, but Kerry said "I am willing ... to take the risk in the effort to put to test the good faith of the Sandinistas."

[104] Meanwhile, Kerry's staff began their own investigations and, on October 14, issued a report that exposed illegal activities on the part of Lieutenant Colonel Oliver North, who had set up a private network involving the National Security Council and the CIA to deliver military equipment to right-wing Nicaraguan rebels (Contras).

Kerry's staff investigation, based on a year-long inquiry and interviews with fifty unnamed sources, is said to raise "serious questions about whether the United States has abided by the law in its handling of the contras over the past three years".

Republicans including President George W. Bush, Senator John McCain and then-Speaker of the House Dennis Hastert, said that Kerry's comments were insulting to American military forces fighting in Iraq.

[122] A Washington Post report in May 2011 stated that Kerry "has emerged in the past few years as an important envoy for Afghanistan and Pakistan during times of crisis", as he undertook another trip to the two countries.

The killing of Osama bin Laden "has generated perhaps the most important crossroads yet", the report continued, as the senator spoke at a press conference and prepared to fly from Kabul to Pakistan.

[123] Among matters discussed during the May visit to Pakistan, under the general rubric of "recalibrating" the bilateral relationship, Kerry sought and retrieved from the Pakistanis the tail-section of the U.S. helicopter which had had to be abandoned at Abbottabad during the bin Laden strike.

[128][129] In July 1997, Kerry joined his Senate colleagues in voting against ratification of the Kyoto Treaty on global warming without greenhouse gas emissions limits on nations deemed developing, including India and China.

[132] In the lead up to the Iraq War, Kerry said on October 9, 2002; "I will be voting to give the President of the United States the authority to use force, if necessary, to disarm Saddam Hussein because I believe that a deadly arsenal of weapons of mass destruction in his hands is a real and grave threat to our security."

"[133] After the invasion of Iraq, when no weapons of mass destruction were found, Kerry strongly criticized Bush, contending that he had misled the country: "When the President of the United States looks at you and tells you something, there should be some trust.

His victory in the Iowa caucuses is widely believed to be the tipping point where Kerry revived his sagging campaign in New Hampshire and the February 3, 2004, primary states like Arizona, South Carolina and New Mexico.

[188] On September 9, in response to a reporter's question about whether Syrian President Bashar al-Assad could avert a military strike, Kerry said "He could turn over every single bit of his chemical weapons to the international community in the next week.

This unscripted remark initiated a process that would lead to Syria agreeing to relinquish and destroy its chemical weapons arsenal, as Russia treated Kerry's statement as a serious proposal.

[211] On April 25, 2021, The New York Times published content from a leaked audiotape of a three-hour taped conversation between economist Saeed Leylaz and Iranian foreign minister Mohammad Javad Zarif.