In MARCH 1930, a rising politician was in a car travelling over a crossroads in Munich. At that moment, a huge truck smashed into it, halting just in time to avoid crushing the passengers inside.

That politician was Adolf Hitler. Three years later, he would become chancellor of Germany before going on to unleash the horrors of the Second World War and the Holocaust, in which tens of millions died.

Would any of that have taken place had Hitler been killed in the accident?

For many, history would have been different without Hitler’s evil ambitions and power. For others, the harsh conditions imposed on Germany after the First World War made another war inevitable. As for the anti-Semitism which fuelled the Holocaust, that was firmly rooted in Germany long before Hitler.

So, do individuals make a difference? And how can we know? Should companies carry on paying their chief executives seven-figure bonuses? Does switching coaches make a difference to a sports team? In this fascinating and far-ranging glance at human history, Jared Diamond, a feted US academic and a Pulitzer Prize-winning historian, looks at the dizzying evidence on all sides of the argument.

On the one hand is the ‘Great Man theory’ – the idea that history is dominated by exceptional leaders from Oliver Cromwell to Jeff Bezos. The rival view is that leaders are constrained by circumstances and have little influence on events. Then there is a middle view, favoured by Diamond: sometimes they make a difference, sometimes they don’t.

To determine this distinction, Diamond has devised the ‘Hamlet test’. If Shakespeare had died of smallpox aged ten, were any other playwrights capable of writing a play as rich and complex as Hamlet?

By 1599, Shakespeare had already written more than 20 plays, including several masterpieces. Could his contemporaries – such as Ben Jonson or Christopher Marlowe – have come close to writing a play so brilliant? Their work is scarcely performed nowadays. So, says Diamond, no one other than Shakespeare could have created Hamlet. He was uniquely talented.

Diamond applies this same test to other exceptional characters. For example, there were many social media sites before and after Mark Zuckerberg launched Facebook in 2004. So, you can’t claim that without Zuckerberg there would have been no social media. But you could say that he is a distinctive personality who caused social media to develop in a certain way.

O nline selling is a modern phenomenon, widely used, but how did Bezos become uniquely successful at Amazon?

In 1988, a computer science professor from Columbia set up a new type of hedge fund, called DE Shaw, hiring computer experts because he recognised that the kind of mathematical modelling made possible by computers was ideal for finance. One of his first hires was a precocious 26-year-old called Jeff Bezos. One of the first tasks he was given was to investigate business opportunities thrown up by the internet. Bezos was amazed to learn that internet use had increased by 2,300 per cent in 1993.

What most excited him was the possibility of an ‘everything store’, a company that didn’t make anything itself but operated as a middleman between consumers and manufacturers, and could supply anything to anyone, anywhere. Bezos left DE Shaw and started Amazon.

Launched using $10,000 of his own money and $1.25million from his parents and investors, the company is now worth $2.8trillion.

So, was it leadership or circumstances that made Amazon so dominant? Bezos had very specific personality traits: he had exceptional attention to detail; he prioritised customer satisfaction – for example, speed of delivery and ease of ordering – over profits and share value; he was relentless and a risk-taker; he retained control over Amazon, thus avoiding the fate of many start-up founders forced out by investors. Many Americans shared one or other of Bezos’s qualities; but only he seized the moment.

But could the success of famous historical leaders depend on their all being born in the right place at the right time?

Fascinatingly, says Diamond, in the case of history’s greatest conqueror, the answer is ‘Yes’. The largest land empire in world history was conquered by the Mongol chief Genghis Khan in the 13th century. Genghis was a military and administrative genius, but so were other leaders on the steppes of central Asia, such as Attila the Hun.

Was Genghis more of a genius than they were? No. What helped him was rain.

T he decades of Genghis’s rise were the wettest on the steppes in modern history. More rain meant more grass for animals, which meant more sheep to eat, more horses to ride, and more Mongol children to ride those horses.

Genghis was brilliant but, had he been born 20 years earlier, his skills would have been wasted.

In a thrilling section, Diamond looks closely at Seretse Khama, founding president of independent Botswana, a landlocked and hitherto poverty- stricken country in Africa. Khama, a brilliant administrator, a gifted athlete, and a former Oxford University student, was able to straddle both modern western and traditional African societies.

When the world’s richest diamond reserves were discovered in Botswana in 1967, Khama used his tribal power to make sure the ensuing wealth became an asset for the whole nation.

Instead of exploiting the diamond revenue, he created a long-term investment fund. He also developed an efficient civil service and was cautious in supporting corrupt and violent black majority governments in nearby African countries. He was the right person in the right place at the right time to create a rich and successful country.

Diamond has a readable style that makes the mind-bending issues he tackles clear.

Why, he wonders, did a tiny Jewish sect built around a charismatic prophet in the Holy Land become the world’s dominant religion?

Part of the answer is Jesus, an eloquent reformer who focused on human behaviour rather than religious laws and rituals. He appealed to all society, including the poor, the sick and women.

Much of the credit for Christianity’s success belongs to the Apostle Paul, the religion’s early organising maestro, who travelled widely through the Roman Empire. He insisted that Christianity should be a religion not just for Jews but also for Gentiles (non-Jews).

There was widespread literacy, which enabled converts to read the emerging New Testament. The literacy appealed most directly to the Roman Emperor Constantine, who went on to adopt Christianity as the religion of his empire.

This is a thought-provoking though sometimes quite chewy book, as Diamond is a serious scientist, albeit one with a staggeringly broad view of the world.