Hovering in the shadows of President Barack Obama's decision last week to ramp up the nation's war effort in Afghanistan, even as he promises to bring it to a swift conclusion, are ghosts of another decision, made 44 years ago by a Texan in the White House.

In 1965, Lyndon B. Johnson took ownership of a war he, like Obama, had inherited. Gen. William Westmoreland wanted more troops in Vietnam, and after a protracted debate within the White House, Johnson sent them.

Over the next three years, he would send hundreds of thousands more and launch a carpet-bombing campaign against North Vietnam. Johnson's presidency – and many argue, Johnson himself – were destroyed long before America could finally, 10 years later, quit Vietnam.

Obama's decision to send 30,000 more U.S. troops to Afghanistan has reawakened those memories of Vietnam's early days, and brought unsettling comparisons from an array of historians who have spent their careers studying Johnson.

Many of those doubts, historians now know, were shared by Johnson himself, as revealed by White House tapes of telephone recordings released to historians over the years. Listening to them again this week chilled some of the men who know best what that decision cost Johnson.