This accessible history book is a good present for anyone who likes modern history but doesn’t want a heavy read.

Ohler is a novelist and the book reads like a novel, but he’s done his research; Ian Kershaw, a world-leading authority on Hitler and Nazi Germany, has described it as “a serious piece of scholarship”.

It’s a book of three halves. The first section describes how the Germany populace, fed up at losing WWI and not having a good time of it, opted to escape by taking drugs; the second about how drugs helped the army (and towards the end, suicidal submariners), and the third Hitler’s own prodigious drug intake.

A few decades before WWII, Germany had led the world in chemical and pharmaceutical research. Friedrich Wilhelm Sertürner isolated morphine, while Heinrich Emanuel Merck, whose company is still going and supplies creams for poorly children, made his money in opium. Merck, Boehringer and Knoll at one point controlled 80% of the world cocaine market. Coca Cola famously really was the real thing.

When a methamphetamine called Pervitin was developed and brought to market, the Germans went mad for it, as a different drug culture would say; it was “a sensation” as a shrink at the time said. Pervitin could treat anything, from lethargy and depression to helping people lose weight and getting a bit of confidence for a party.

This background leads onto the first meaty section, the invasion of Poland. This was made easier by giving the troops industrial quantities of drugs, so they could stay awake longer.

“Everyone fresh and cheerful, excellent discipline. Slight euphoria and increased thirst for action,” said one report from the front. Even if one side effect was double vision it didn’t matter, as the men had enough energy to kill everyone twice.

From here it was a natural step to use it to help Germany kick-start the war proper: give it to the panzer divisions and let them sweep across Europe and into France before Winston Churchill had the chance to slurp his second Carlsberg Special of the day. Blitzkrieg was here, possibly because the army needed no sleep.

Drug use was widespread and went to the top: Adolf Hitler was seen as a vegetarian teetotaller who would allow nothing to corrupt him (and was for a time) but was also keen on anything to make him even healthier. Enter Dr Theodor Morell, who thanks to liberal if scruples-free “vitamin” injections, became Hitler’s personal doctor. His “vitamins” were often enhanced with non-vegetarian extracts, the presence of meat-based products not getting in the way of Morell’s ambition to enrich himself by helping his fuhrer.

From pig’s liver and heart to cocaine and morphine, Hitler’s system soaked it all up, and in the end Hitler was a smackhead — indeed, Ohler says that at the end, as drugs ran out, Hitler was forced into cold turkey.

It’s a fascinating book. The main criticism for me is that it focuses narrowly on Hitler’s drug abuse, which is darkly comical: Hitler is a drug-addled idiot. Yet you know that outside Hitler’s closely guarded bunkers, people are dying in their millions. Ohler doesn’t intend to trivialise and never underplays the atrocities, but it is a necessarily restricted view (as was Hitler’s, in his bunker). An interesting read, not too academic and not too long.

Norman Ohler’s Blitzed: Drugs in Nazi Germany is published by Allen Lane.