For Hitler, though, a crisis was coming. When the factories where Pervitin and Eukodal were made were bombed by the allies, supplies of his favourite drugs began to run out, and by February 1945 he was suffering withdrawal. Bowed and drooling and stabbing at his skin with a pair of golden tweezers, he cut a pitiful sight. “Everyone describes the bad health of Hitler in those final days [in the Führerbunker in Berlin],” says Ohler. “But there’s no clear explanation for it. It has been suggested that he was suffering from Parkinson’s disease. To me, though, it’s pretty clear that it was partly withdrawal.” He grins. “Yeah, it must have been pretty awful. He’s losing a world war, and he’s coming off drugs.”

The team found what they were looking for during one of the Predator’s very first split operations missions in early September 2000. Swanson was circling over Tarnak Farms, a walled compound near the Kandahar airport where bin Laden-or UBL as the team called him, referring to the alternative spelling, Usama-was thought to be living. Jeff Guay, an Air Force master sergeant on the team, was controlling the drone’s camera. Sure enough, a man in white, surrounded by an entourage, soon emerged on their screens.

“When UBL walked out of that one building,” Swanson says, “the way he appeared much taller than everybody, the people were deferential around him, the way he was dressed, Jeff and I just looked at each other and it’s like, ‘Yeah, that’s got to be him.’” Swanson assumed a cruise missile would be dispatched in the direction of bin Laden while the Predator loitered overhead to make sure he stayed put. The team had been instructed to continue circling for as long as necessary, even if that meant running out of fuel and crashing.

But for reasons obscure to the team, no strike was ordered. With Swanson gripping his joystick, unable to do anything but stare, America’s final chance to kill Bin Laden before September 11 slipped away.

These questions should inspire two feelings. The first is humility. We can never know what a universe without Hitler would have looked like. But the implicit argument that his removal would improve history must also consider that his removal could make it worse. Indeed, recent experience should make us doubt our abilities to bend the course of human events towards our will. The Bush administration naively claimed that toppling Saddam Hussein in 2003 would produce a vibrant liberal democracy in the largely illiberal Middle East. Instead it brought about regional instability, ethnic cleansing, civil war, and ISIS.

The second is relief. We live in cynical times, which masks the fact that we live in extraordinary times. Atrocities still occur, but human rights are now a normative value throughout most of the world, even if their enforcement is imperfect. Conflicts are still fought, but the great powers have avoided another world war for seven decades. Racism and anti-Semitism still exist, but pre-war forms of colonialism and pogroms have largely disappeared. This is not the future for which Nazi Germany fought and fell. Removing Hitler from history would gamble with one irrefutable truth: He lost.

Our ignorance of the Islamic State is in some ways understandable: It is a hermit kingdom; few have gone there and returned. Baghdadi has spoken on camera only once. But his address, and the Islamic State’s countless other propaganda videos and encyclicals, are online, and the caliphate’s supporters have toiled mightily to make their project knowable. We can gather that their state rejects peace as a matter of principle; that it hungers for genocide; that its religious views make it constitutionally incapable of certain types of change, even if that change might ensure its survival; and that it considers itself a harbinger of-and headline player in-the imminent end of the world.

The Islamic State, also known as the Islamic State of Iraq and al-Sham (ISIS), follows a distinctive variety of Islam whose beliefs about the path to the Day of Judgment matter to its strategy, and can help the West know its enemy and predict its behavior. Its rise to power is less like the triumph of the Muslim Brotherhood in Egypt (a group whose leaders the Islamic State considers apostates) than like the realization of a dystopian alternate reality in which David Koresh or Jim Jones survived to wield absolute power over not just a few hundred people, but some 8 million.

The Goldsboro bomb that almost detonated was known as Weapon No. 1. As the plane was spinning and breaking apart, the centrifugal forces pulled a lanyard in the cockpit–and that lanyard was what a crew member would manually pull during wartime to release the bomb. This hydrogen bomb was a machine, a dumb object. It had no idea whether the lanyard was being pulled by a person or by a centrifugal force. Once the lanyard was pulled, the weapon just behaved like it was designed to.

The bomb went through all of its arming steps except for one, and a single switch prevented a full-scale nuclear detonation. That type of switch was later found to be defective. It had failed in dozens of other cases, allowing weapons to be inadvertently armed. And that safety switch could have very easily been circumvented by stray electricity in the B-52 as it was breaking apart. As Secretary of Defense McNamara said, “By the slightest margin of chance, literally the failure of two wires to cross, a nuclear explosion was averted.” That’s literally correct, a short circuit could’ve fully armed the bomb.

In those days in Munich I lived in the Thiersh Strasse, and I frequently noticed in the street a man who vaguely reminded me of a militant edition of Charles Chaplin, owing to his characteristic moustache and his bouncing way of walking. He always carried a riding whip in his hand with which he used incessantly to chop off imaginary heads as he walked. He was so funny that I inquired from neighbours who he might be: most of them, owing to his Slav type, took him to be one of these Russian émigrés who abounded in Germany at that time, and they freely talked of his being probably a trifle mentally deranged. But my grocer told me it was a Herr Adolf Hitler from Braunau in Austria, and that he was leader of a tiny political group which called itself the “German National Socialist Workers Party”. He lived as a boarder in the apartment of a small artisan, wrote articles for an obscure paper called the Völkischer Beobachter, and orated in hole-and-corner meetings before audiences of a dozen or two. Out of curiosity I bought the paper once or twice, and found it a scatter-brained collection of wild anti-Jewish stories and articles interlarded with panegyrics on the Germanic race. My obliging grocer closed his information on Hitler by remarking that he frequently purchased things in his shop and was, despite his eccentric appearance, quite a pleasant fellow, though inclined to talk sixteen to the dozen about anything and everything.

First he laid out his Crye Precision Desert Digital combat uniform, a long-sleeve, partially camouflaged shirt and cargo pants combo with ten pockets, “each with a specific purpose.” In the pockets he put assault gloves, leather mitts for “fast-roping,” an assortment of batteries, energy gel, two PowerBars, an extra tourniquet, rubber gloves, an SSE (forensic) kit, an Olympus point-and-shoot digital camera, and $200 in cash. The money was for a bribe or a ride, if needed. “Evasion takes money, and few things work better than American cash.”

Archaeology magazine highlights the presence of spherical magnetic shards-remnants of the D-Day operations of World War II-found hidden amongst natural sand grains on the beaches of Normandy. “Up to 4 percent of the sand is made up of this shrapnel,” the article states; however, “waves, storms, and rust will probably wipe this microscopic archaeology from the coast in another hundred years.”

‘The rest of the investigation that Tamim conducted, however, was meticulous and efficient in a way that no one, least of all the Mossad, had expected. A source close to the investigation said that the moment Tamim concluded that Al-Mabhouh had not died of natural causes, he ordered his people to search Dubai’s extensive databases and identify everyone who had arrived in the emirate shortly before the killing and left soon after. This list was then cross-referenced against the names of visitors who had been in Dubai back in February, March, June, and November of 2009, all the times of Al-Mabhouh’s previous visits. The short list that emerged was then checked against hotel registers, and footage from hotel security cameras at the times these individuals checked in made it possible to put a face to each name. Tamim then compared these visual identifications to the footage from the Al Bustan Hotel at the time of Al-Mabhouh’s death, which gave him the names of the assassins. And searching databases of financial transactions gave him the identities of the rest of the team, all of which Dubai authorities posted online for the world to see.’

He had sold, he believed, between 25 and 35 million copies of The Longest Day and 400,000 hardcover copies of The Last Battle in the United States alone. Yet each book had cost him some $150,000 to research. “I have no less than 7,000 books on every aspect of World War II. My files contain some 16,000 different interviews with Germans, British, French, etc,” he wrote. “Then there is the chronology of each battle, 5×7 cards, detailing each movement by hour for the particular work I’m engaged in. You may think this is all a kind of madness, an obsession. I suppose it is.”

He also told the German newspaper how he was dismissed by Hitler over a bizarre incident involving a fly.

The fly had been buzzing around the room during a strategy conference in July 1944, irritating the Nazi leader.

Hitler ordered Mr Darges to get rid of it, but the SS adjutant suggested that as it was an “airborne pest” the job should go to Luftwaffe adjutant, Nicolaus von Below.

He said Hitler then flew into a rage and dismissed him, saying: “You’re for the eastern front.”

‘Human beings are proud of what they create-no matter how controversial or deadly. Edward Teller revealed the essential secrets of the hydrogen bomb in a popular encyclopedia article. In 1995, Robert Henderson, the chief engineer for the Manhattan Project, sent back to Coster-Mullen an early version of the “Atom Bombs” manuscript, with comments such as “shit” and “pure shit,” and then went on to explain the exact (and still classified) process by which engineers made the lens molds that cast the explosives that squeezed the core of Fat Man until it achieved critical mass. Reading through President Truman’s diaries, at the Truman Library, in Independence, Missouri, Coster-Mullen found an entry dated July 25, 1945, in which the President marvelled that “13 pounds of the explosive” had made the shot tower at Alamogordo, New Mexico, disappear-a pretty accurate estimate of the amount of nuclear material contained in Fat Man.’