W. Averell Harriman (1891-1986) was a U.S. businessman, elected official, government advisor and diplomat. As heir to the Union Pacific railroad fortune,he was by 1932, its chairman of the board, as well as being involved in shipbuilding and international finance ventures. He then spent his career in out of government service. He was known to be a rough negotiator and was called "the alligator" for his style within the government.
Within the advisory elite, David Halberstam wrote that Harriman would always have "a certain taint, as if somehow Averell was too partisan and too ambitious; [he] had wanted to be President whereas the rest of them knew the real power lay in letting the President come to them...Averell had, after all, — there was no getting around it — run for public office and won; he seemed too much the politician and too much the intriguer for them. Perhaps not as bad as Roosevelt, but not one of them, either."
Second World War and Postwar
Along with Armand Hammer, he was one of the first Americans to seek business with the relatively new Soviet Union. He then became a diplomat to the USSR in 1941, first as minister and then ambassador. After the war, he was briefly ambassador to the United Kingdom, and then returned to Washington as an adviser to Harry S. Truman, beginning as Secretary of Commerce. He consulted on the Marshall Plan as the U.S. representative in Europe under the Economic Cooperation Act of 1948, with rank of Ambassador Extraordinary and Plenipotentiary, 1948-50; and then, during the Korean War, was Assistant to the President for National Security Affairs between 1950-51. Returning to Europe, he was the American representative on the North Atlantic Treaty Organization defense policy planning committee and director of the Mutual Security Agency, 1951-53.
Enterig politics in 1954, he served one term as governor of New York, losing a second to Nelson Rockefeller. He then ran twice for the Democratic presidential nomination.
He held a number of diplomatic positions in the Kennedy, Johnson and Nixon Administrations, among which were negotiating the first Treaty on the Non-Proliferation of Nuclear Weapons . Kennedy rejected his proposal to implement the Geneva 1954 accords in a way that would have abandoned South Vietnam.
Harriman had supported the 1963 coup against Ngo Dinh Diem. Ambassador to South Vietnam Frederick Nolting Jr. believed he gave bad advice on Vietnam to Kennedy. Nolting said he could not understand that when Lyndon Johnson "inherited this mess, what I can't understand is why he didn't do something about the advisers of President Kennedy who had created it. They were principally Averell Harriman, whom he kept on, Cabot Lodge, whom he not only kept on but reappointed to the ambassadorship out there." At various places in the LBJ Library Oral History, he variously spoke of Harriman as supportive of him and attacking him.
In March 1964, Harriman advised Johnson to make economic offers to North Vietnam.  Harriman then became Johnson's Ambassador-at-Large for Southeast Asian Affairs in 1965, investigating ways to end the Vietnam War. Johnson, in 1966, sent him to Moscow to try to get support in restarting the Geneva conference on Vietnam.  Robert McNamara said Harriman agreed, in 1966, the North Vietnamese would never surrender, and the U.S. must accept a coalition government.
In 1968, he served as chief US negotiator when the overt preliminary peace talks opened in Paris between the US and North Vietnam. The serious talks, however, were held in secrecy between Le Duc Tho and Henry Kissinger.
He disapproved of Nixon's handling of the Vietnam war and the peace talks, writing on July 15, 1971, that the North Vietnamese had offered a "reasonable way" to end the war. 
- Halberstam, David (1972), The Best and the Brightest, Random House, p. 6
- Henry Kissinger (1973), Ending the Vietman War: A history of America's Involvement in and Extrication from the Vietnam War, Simon & Schuster, p. 33
- McMaster, H. R. (1997), Dereliction of Duty: Johnson, Pike, the Joint Chiefs of Staff, and the Lies That Led to Vietnam, Harpercollins, pp. 39-40
- Gittinger, Ted (November 11, 1982), Oral History interview of Frederick Nolting, Lyndon Baines Johnson Presidential Library, p. I-33
- McMaster, p. 161
- Robert S. McNamara (1995), In Retrospect: the Tragedy and Lessons of Vietnam, Times Books division of Random House, pp. 195-196
- McNamara, p. 300
- Kissinger, p. 216