The JFK Conspiracy: The Secret Plot to Kill Kennedy and Why It Failed by Brad Meltzer and Josh Mensch (Ithaka Press £25, 304 pp)

The Solomon Islands, South Pacific, August 2, 1943. An ink-black moonless night, and an 80ft US Navy motor torpedo boat, with just 13 crew aboard, is patrolling the Blackett Strait.

Only one of its three engines is running, to stay as quiet as possible. There are Japanese warships close by, and these are on high alert. Suddenly, at 2.30am, a desperate cry goes up from one of the crew. ‘Ship at two o’clock!’

Then they all see it, the huge louring outline of a Japanese destroyer bearing straight down on them. The lieutenant in charge spins the wheel furiously to starboard so they can fire off a torpedo broadside. 

But with only one engine running, the small patrol boat is too slow, and the destroyer is approaching at a blistering 32 knots or 37 mph.

They’re not even sure if the destroyer has seen them – and then it smashes straight into the boat. An explosion of flames. Two crewmen killed instantly. Others badly injured . . . And the destroyer churns on into the warm, tropical night, certainly not pausing to pick up any enemy survivors.

The name of the young lieutenant on the patrol boat is John F Kennedy. A tall, lanky, tanned 26-year-old with a winning smile. Girls find him irresistible.

What follows for him and his men over the next few days is a harrowing mix of survival epic and horror story. Despite back injuries, Kennedy swims thorough pools of flaming oil to rescue his badly burned machinist, Patrick McMahon.

Clinging to the debris of the boat, the crew float through the night until sunrise – and then the terrible dehydration starts. Later, they swim an incredible three miles to the nearest island to find water or help. 

Kennedy swims pulling McMahon along by a life jacket strap clenched between his teeth. He used to be on the swimming team at Harvard. The rest cling to any spars they can find.

It’s another terrible six days before they are rescued.

When JFK later entered politics, having such an impressive war record, and a Purple Heart to prove it, surely did his prospects no harm. It’s also true, say the authors, that those who have endured extremes like this horror in the South Pacific, and looked so closely on death, tend not to worry about the small stuff later in life.

Certainly, once sworn in as president in January 1961, the youngest ever in one of the closest and most bitterly contested elections in US history (the popular vote was 34,226,731 for Kennedy, 34,108,157 for Nixon), Kennedy remained markedly relaxed when it came to security. Instead of such anxieties, he represented youth, confidence, optimism and progress over his conservative rival.

One other thing: he was the first Catholic in the White House.

To many traditional American Protestants this was discomforting, but for one man it became a murderous obsession.

We all know about Lee Harvey Oswald and that dreadful final day in Dallas. 

The full horror will never be forgotten: gunshots – the president suddenly lolling to his left, grabbing his throat – the desperate reaction of the Secret Servicemen, jumping on to the limousine’s running boards, ready to take any more shots themselves – and then the headshot, and his wife Jackie scrambling out across the boot of the car to retrieve something – part of her husband’s skull . . . It was enough to traumatise a nation for years.

But it is an earlier attempt on Kennedy’s life which is revealed in this mesmerising new account, and the bizarre story of retired postal worker Richard Pavlick, a bad-tempered loner and head of the Protestant War Veterans Legion.

Pavlick saw Catholicism as a foreign influence and a Catholic president as a leader of divided loyalties. America must be saved.

With Kennedy having won the election on November 8, 1960, a furious Pavlick drove an hour from his Belmont home to the New Hampshire Machinery and Explosives Company, and bought a stick of dynamite. 

He bought more over subsequent days, ending up with eight: enough, said the store owner, to ‘destroy a good-sized building’.

This wasn’t illegal, but the owner did ask what it was all for.

‘Tree stumps,’ said Pavlick.

He made his will, left his house to a local youth club, and set off south for Florida and the Kennedy mansion known as the Winter White House, the 11-bedroom La Querida in Palm Beach. Pavlick told a colleague back home: ‘I came down to die, you will see it on TV.’

To another, Thomas Murphy, he said, quoting Jesus’s own words, that he was going to ‘prepare a place’ for him.

‘He scared me,’ said Murphy.

It was all too easy. In Palm Beach, JFK and his family attended Mass at St Edward’s Catholic Church, only a five-minute drive from La Querida. The Secret Service would have a limousine waiting on North Ocean Boulevard, right outside the Kennedy residence.

Pavlick’s less impressive green 1950 Buick had one extra feature: eight sticks of dynamite in the boot. Sufficient to devastate half a street.

The moment the president walked through the gate of his mansion, the assassin could start his engine and drive straight into him, an all-American suicide bomber.

But what time would Kennedy appear? Surely a key element in security is keeping your asset’s timetable secret, and highly variable?

Not back in 1960, not with the blasé, confident war hero Kennedy. St Edward’s Church listed its service times; Mass was at 10am, and Kennedy would leave the house about ten minutes beforehand.

At 9.50am, no one paid much attention to the Buick parked close by. It was a public street, after all.

The front gates of La Querida swung open, out stepped that familiar figure, tall and tanned.

Pavlick reached for the ignition key. And then two other figures appeared in the gateway. A woman and a child.

It was Jackie Kennedy, their son John Jr and three-year-old daughter Caroline, her reddish-brown hair shining in the Florida sunshine. Pavlick froze. Obsessive loner he may have been, but he was no monster, no cold-blooded child killer.

Suddenly the president wasn’t an abstract target but a man with a wife and children.

Pavlick fled the scene.

But he couldn’t let it go, and later returned to inspect the church itself, planning his next assassination attempt. By this time the Secret Service were on to him: comments he had made to people back home had been reported to the police, and the net was closing.

Pavlick was finally arrested for threatening the president’s life, and was later committed to a mental institution because he was judged mentally ill and unable to distinguish between right and wrong. He died in a veterans’ hospital in 1975.

JFK was said to be merely ‘bemused’ by Pavlick’s plot.

Kennedy, the authors summarise, was ‘charismatic, generous, a beacon of idealism and inspiration’. Yet he was also, ‘selfish, arrogant and reckless’.

In one ugly revelation, it appears Kennedy was cavorting on a yacht with a mistress while Jackie was in hospital having a miscarriage.

Still, he was an iconic figure, the golden boy of an America that might have been, of a particular moment in time – and a lightning rod for disaffected loners like Richard Pavlick.