The whole concept of temporal ethics began with the assassination of John F. Kennedy.  The historians who perpetrated the president's murder believed it would help end the Vietnam War earlier.  In a way they were correct.

Prior to his death, Kennedy allowed the Vietnam War to continue through all eight years of his presidency.  While this primarily stemmed from the military industrial complex blackmailing him, thanks to Kennedy's affair with Marilyn Monroe, the blame is no less on his shoulder.  On the voter's side of blame, because of Kennedy's civil rights initiatives, which some suspect may have been his way of atoning for the war, Lyndon Johnson rode into office under the pretense of being Kennedy's successor.  However, Johnson didn't need any bribery to continue in the conflict.  He took the cold blooded stance that the war fueled industry, and as such produced jobs for Americans.

Fortunately, Johnson only served one term, and President George Mcgovern ended the war.  But an entire generation of young Americas were either dead , or so ruined by their experiences the nation would never really recover.  

Researchers in 2355 examined this timeline.  After months of painstaking work, they discovered 3 surviving alternative branches.  While all realities are possible we now know for the fraction of a second it takes for each possibility to coalesce into a distinct reality time becomes stretched thin as it expands to accommodate the infinite outcomes.  This stretching results in tears which permit one outcome to exist at the same time as another.  In essence, one universe suddenly inhabits the same space as another.  The result is typically cataclysmic; the universes annihilate one another.  However, those which survive become alternatives to the reality that we are aware of.  

History is rarely clean.  In one of the alternative Kennedy timelines (hereafter referred to as K-1, 2, and 3 respectively), Kennedy stepped down after his mishandling of the Cuban Missile Crisis, and the nuclear annihilation of Cuba.  K-3 had Kennedy openly admit to his affair with Marilyn Monroe, and took the edge off the scandal by becoming the first president to openly divorce and remarry while in office.  The Vietnam war ended in this timeline during Kennedy's second term.  This then begs the question why historians chose the causation of K-2, the assassination.  

Kennedy's open divorce left a bad taste in many conservatives mouths (or as some have supposed the sweet taste of opportunity).  As such an entrenched collective of senators and representatives emerged who bitterly opposed any legislation the president put forward.  Acting on behalf of what they called the moral majority, a large portion of Congress prevented the passing of several Civil Rights bills.  Without any real sense of progress, the peaceful side of the civil rights movement eventually disbanded save for a few ardent believers.  More radical groups took up the cause militarizing it.  On a darker note, feeling the government had just subtly declared their opposition to minority rights, white power organizations began popping up all over the country promising to protect white America from these more aggressive Civil Rights advocates.    

It is entirely possible a reality once existed where the aforementioned situations were all handled with grace and dignity.  However, those didn't survive the expansion of time.  So historians went with what was perceived as the best of three bad options.  K-1 left the word too close to the brink of nuclear suicide, and K-3 resulted in the radical marginalization of millions -- what kind of world would historians be creating?  

Keep in mind these were the early days of temporal manipulation.  Pioneers like James Reese and Elizabeth Hardwell had yet to discover what are known as phantom filaments, the ghostly remains of annihilated timelines, and so historians at the time of the Kennedy Decision felt they had only the three options.  So, in their own words, "We chose a reality wherein the fewest negative outcomes occurred."

It almost sounds like the right thing to do.  Professor Winston Smith, who took part in the Kennedy Decision, put it best when he wrote in his memoir, "In the face of monstrosities humans often feel compelled to act.  Now that the Past is no longer immutable it seems as if we have a moral obligation to correct the great, hideous mistakes.  However, choosing the lesser of two evils still results in choosing evil."

So it was that humanity, for the first time, changed its Past.  The problem we're left with now is where to stop.

- Op-ed written by Lawrence Jones for the Journal of Temporal Ethics, issue #13, July 16th, 2398