, about three months of which were spent in Vietnamese waters; he served in Vietnam on Swift Boats as part of Coastal Division 13 (3.5 months) and Coastal Division 11 (8 months) from 1969 to 1970, during which time he was awarded two Bronze Stars.
Thus, O'Neill appears to have spent a total of about 15 months in or off the coast of Vietnam. He is said to have spent some time in a military hospital with a damaged knee and leg upon returning home, but O'Neill has not claimed, nor do his military records indicate, that the damage was sustained in combat. In this connection, he received no Purple Hearts during his service years.Some of O'Neill's claims about his length of service in Vietnam conflict with the records of his service there. For example, on several occasions he claimed to have served in Vietnam "almost three years"
, although his records, as described above, indicate that he actually served no more than about 15 months there. Additionally, he claimed to have served "much" of a two year period "in waters adjacent to Vietnam"
, to have served in Coastal Division 11 for one year
, and to have served 18 months "in the same place" Kerry served
; none of these timelines match the above records. And although he wrote that he "took over [Kerry's boat] after he requested early departure,"
the records indicate that he took command of PCF 94 more than five months after Kerry left Vietnam (see above).
O'Neill stated that he believed the committee hearings were creating a false impression of popular opinion about Vietnam veterans, and that he contacted the committee, offering to provide additional testimony
he believed would contradict Kerry’s, but that his request was denied. Richard Nixon's former special counsel Charles Colson has stated that he recruited O'Neill to be a "counterfoil" to John Kerry
Kerry had come to prominence as part of the Vietnam Veterans Against the War, and had become a particular target for the White House since his appearance before the Senate Foreign Relations Committee.
O'Neill was at the center of the new organization, Vietnam Veterans for a Just Peace, and he became a media figure defending the Vietnam war and criticizing opponents of the war. O'Neill first met Kerry during a debate on the Dick Cavett Show on June 20 1971.
O'Neill strongly defended American incursions in Laos and Cambodia, and opposed anti-war veterans. He was particularly critical of Kerry's claims regarding the commission of war crimes by U.S. military personnel in Vietnam.

O’Neill subsequently returned to Texas to practice law, specializing in commercial litigation. He later co-founded the law firm Clements, O’Neill, Pierce, Wilson, and Fulkerson in Houston. His partners at that firm included, among others, Margaret Wilson, who once served as general counsel for George W. Bush during his time as governor of Texas, and the late Tex Lazar, who once ran for lieutenant governor on the same ticket with Bush and who died in 2003. The firm was recently subsumed into the larger Howrey LLP
According to his most recent firm resume, in addition to practicing oil and gas litigation, O’Neill obtained one of the largest securities arbitration judgments in history representing a small-time investor who had been defrauded by a large securities company, and also successfully represented a class of immigrants in a suit against Fiesta, allowing them to recover their money when the savings and loan went under
The "Texas Lawyer" magazine reported on February 19 and 26, 1990, that O'Neill, who was representing the plaintiffs in a securities fraud class action underlying a malpractice suit, and two other lawyers were threatened with sanctions for allegedly violating the Texas Code of Professional Responsibility by the judge in the case, United States District Judge David Hittner, who declined to pursue the matter after the trial was completed.
In 1991 O'Neill was considered by President George H. W. Bush for nomination as a federal judge in Texas, but was passed over.
He has stated that he voted for Al Gore in 2000, and Ross Perot in 1996 and also in 1992, although records indicate he donated to the 1992 Bush-Quayle primary campaign
He has stated that he admired Democrat John Edwards during the 2004 Democratic primary but did not claim to have voted for him in that primary. However, with the exception of the 2000 election, he has not claimed to have voted for any Democratic presidential candidate since Hubert Humphrey in 1968. While he told Richard Nixon in 1971 that he had not voted for him in the 1968 election, he seconded Nixon's nomination at the 1972 Republican national convention
Available records indicate he voted in the Republican state primary in 1998 and has regularly contributed to the Texas Republican Party and to Republican candidates for federal office
None of the available records indicate donations to the state Democratic Party or to any Democratic candidate for federal office. However, O'Neill has claimed to have made large contributions to local Democratic candidates and supported Bill White and Ron Green for the nonpartisan positions of mayor and city councilmember, respectively, of the City of Houston.
In this connection, O'Neill's name appears on an endorsement for Bill White
O'Neill is a director of the conservative David Horowitz Freedom Center (formerly the Center for the Study of Popular Culture), co-founded by David Horowitz; the center also publishes the online FrontPage Magazine
O'Neill sent a letter supporting Greg Parke, an unsuccessful candidate for the Republican nomination in the 2006 race for the Senate seat for Vermont.
He has also endorsed the Presidential campaign of Duncan Hunter.