This article is from 2010, but the math still adds up. From NPR:
Afghanistan hasn’t become the U.S.’ longest war; Vietnam still is, according to someone who should know, Richard Holbrooke, the Obama Administration’s special representative to Afghanistan and Pakistan, who also served as a young American diplomat in Vietnam.
Holbrooke spoke with All Things Considered co-host Robert Siegel Monday (we’ll provide a live link when it becomes available) and took issue with what he sees as a revisionist history being peddled by some in the media who are dating the start of Vietnam to the Gulf of Tonkin Resolution in 1964.
President Lyndon Johnson got Congress to pass the resolution on what many historians consider the trumped-up pretext of a North Vietnamese attack on a U.S. warship …
Read more here.