The assassination of John F. Kennedy in 1963 was a pivotal point in American history, which is why historians, both amatuer and professional, often wonder – what would have happened if that pivot had gone the other way? What would the world have been like if JFK had not been killed? What if he had lived a long life, had served a second term, and led America through the heart of the turbulent 1960s?

Many have tried to answer that question over the years, though with varying degrees of expertise. If we are to believe these speculative alternate histories, the dominos from his assassination careen in every which way. In some of these visions, a world with John Kennedy is a world without hippies; with a peaceful US-Cuba relationship, with less war (or more war); or a world with an aging, divorced, wheelchair-bound elder statesman with all his flaws exposed. Either that, or a nuclear holocaust. Who really knows? Below are some of the more popular theories and fantasies to come out of the JFK speculation business.

No Escalation in Vietnam

That Kennedy would not have escalated in Vietnam is perhaps the most tantalizing "What If" in JFK fan fiction pieces. There is some solid evidence to support that case, including a note from Kennedy to his staff the day before traveling to Dallas calling for "an in-depth study of every possible option we've got in Vietnam, including how to get out of there." JFK biographer Robert Dallek, the author of Camelot's Court, falls into this camp, as he told The Wall Street Journal. "Most importantly, there's reasonable speculation that he would have gotten out of Vietnam. Or at least never have put those massive numbers of ground troops into Vietnam that Lyndon Johnson did," Dallek said. Jeff Greenfield, the author of If Kennedy Lived: An Alternate History and a foremost JFK-speculator, agrees as well. Kennedy resisted military calls for nuclear escalation during the Cuban Missile Crisis, and so Greenfield speculates that he could resist diving further into Vietnam.

The power that comes with a second term would have helped, too. H.W. Brands, a University of Texas history professor and JFK author, argues that a second-term JFK would have been able to make the unpopular decision to leave Vietnam alone. "And if he had won a second term, his lame-duck status would have granted him a certain political freedom denied to presidents who have another race to run," he wrote in The Washington PostLame ducks can sometimes make tough decisions; those running for reelection have to be more guarded.

What would this speculative de-escalation have looked like? There's an answer for that, too. Edward Miller, the author of a book on the U.S. and South Vietnam, speculates that JFK's departure from Vietnam would actually look a lot like Obama's plan for Afghanistan: a short burst of escalation followed by a phased withdrawal, Miller told Here and Now Radio

No Hippies

Not dragging the U.S. into Vietnam also effectively cuts off the counterculture movement, Greenfield speculates. That means no hippies, no beatniks, no draft dodgers, no tie-dye clothing, and no Woodstock in this alternate world. The 1960s without an active anti-war movement would be a much different place.

Better Parties

A second JFK term would not just mean a smaller war with Vietnam: It would mean more parties! Greenfield imagines a monstrous second inaugural gala, featuring performances from the Beach Boys, Roy Orbison, and The Beatles. Greenfield gets weirdly specific about what happens at the party, including this hypothetical JFK quote: "Not since the British burned the White House in 1812 has a foreign invader conquered our land as swiftly and thoroughly as have John, Paul, George, and Ringo."

Rapprochement with Cuba

"If he had lived, there's lots of speculation — and I think with good reason — that he might have achieved some kind of rapprochement with Cuba," Dallek said to the WSJ. "And so the long history of Cuban-American alienation would not have occurred." Dallek made that case even stronger in The Atlantic in 2003. Partly out of distrust for his military advisors, Kennedy saw deescalation with Cuba as the only solution to their issues. 

That explains why Fidel Castro himself was so distraught by JFK's death, as The Atlantic's Jeffrey Goldberg chronicled on Wednesday. "He understood, he said, that he would be blamed for J.F.K.’s death, especially after it was learned that Oswald had vociferously opposed American policy toward Castro’s Cuba," Goldberg writes. To assuage U.S. concerns, Castro took the extraordinary step of arranging a meeting with Warren Commission officials to explain that he played no role in the assassination. The public wasn't quite as convinced, as the Cuban connection remain a key plank of many assassination conspiracy theories and the U.S. embargo of Cuba continues 50 years later.

No President Lyndon B. Johnson

Kennedy's assassination was great for Johnson's political career, as it saved him from a coming scandal. "A corruption investigation into the vice president, also very real, was shelved by the editors at Life magazine in the sensitive weeks after Kennedy was killed," NBC News writes in a review of Greenfield's book. Without Kennedy's death, Johnson's scandal is fair game and he is forced to resign and trek back home to Texas, so Greenfield imagines. Even without the scandal, Kennedy might have chosen to back his younger brother for the White House in 1968, continuing the family dynasty. He already expressed doubts about keeping Johnson on the ticket in 1964.

No Civil Rights Legislation

Would Kennedy have passed the Civil Rights Act, the Voting Rights Act, or the Fair Housing Act that Johnson undertook? The consensus among Kennedy speculators is no. "Kennedy had to be dragged to civil rights," says Larry Sabato, the author of The Kennedy Half Century. Sabato suggests the Civil Rights Act would have been passed, but the VRA and Fair Housing Act would not. Greenfield disagrees, and doesn't even think the Kennedy would have passed Civil Rights. Given the unpopularity of his (speculative) Vietnam withdrawal, Kennedy wouldn't have risked losing Southern Democrats by passing civil rights, according to Greenfield. He also would have struggled to do so without Johnson, "a Southerner who could speak to Southerners in their own language, and a legislator in chief par excellence," writes Brands. Johnson helped sell civil rights; Kennedy couldn't have done it by himself.

A One-Term Loser

An alternate to these alternate histories is that Kennedy never even gets to a chance to do any of these things, because he doesn't get re-elected in 1964. There is evidence that Kennedy himself worried about that prospect and there's no telling what the politics of the following year might have brought, especially if he had continued down the road to war in Vietnam and/or failed to pass the Civil Rights Act, cementing a key victory for the Democratic Party.

JFK Is Not Well Regarded

Even assuming all of those things are true — he isn't killed, he gets his second successful term, and retires comfortably — it's still likely that he wouldn't be viewed nearly as warmly by the general public today. "I don't know that he would have the kind of reputation and standing now, because every second-term president has to deal with a variety of difficulties, problems that are going, to one extent or another, diminish their standing or reputation," Dallek said to WSJ. One of those difficulties just might have been exposure of Kennedy's rampant dalliances, which would have had major consequences on his personal and political life. Greenfield suggests that Jackie would have contemplated a separation if the affairs continued. "By ‘68, the women's movement was beginning to take shape and maybe Jackie Kennedy might have looked for a different kind of life at the end of the term,” Greenfield told Yahoo News. The White House press corps had a close relationship with Kennedy and so didn't expose his affairs in those days, but that wouldn't have lasted that long. "Sooner or later it would have come out. My bet is after the second term." Sabato said to Discovery News. A post-Watergate (assuming Watergate even happened!) media landscape would not have been so kind.

JFK's medical problems would have caught up to him as well, and Greenfield suggests that his well-documented spine issues would have eventually robbed him of his ability to walk. Would he have tried to hide that handicap from the public like Franklin Roosevelt did? Would a wheelchair-bound president have inspired the same mythology?

Nuclear dystopia

There are many other speculative fictions surrounding the Kennedy story, including fanciful tales made specifically for fiction, and not serious historical scholarship. One of the more recent ones, dreamed up by Stephen King in his time-traveling book 11/22/63, sees a man goes back in time to stop JFK’s assassination. The result? (Spoiler alert.) No Civil Rights law, President George Wallace in 1968, hyper-escalation to nuclear weapons in Vietnam, and a modern world besieged by nuclear holocaust and rampant natural disasters. Not exactly the feel good ending we were all looking for.

(Images from Reuters)