Top 10 Human Mistakes That Changed History Forever

During the Cold War, the US backed numerous coup d'états around the world. While several of these succeeded in installing new regimes, attempts in Cuba failed spectacularly. Worried about Prime Minister Fidel Castro’s communist policies, in 1961 the CIA orchestrated the infamous Bay of Pigs Invasion - landing Cuban counter-revolutionaries on the country’s southwestern coast. However, an obvious paint job on a B-26 bomber, disguised to look Cuban, gave away US involvement to the world - leading President Kennedy to pull back air support. A few days later, a last ditch bombing raid flying out of Nicaragua was botched when bombers were caught without their escort of fighter jets. Embarrassingly, someone had forgotten the one hour difference between Nicaragua and Cuba.

Scottish physician Alexander Fleming was a brilliant researcher, most famous for his work on bacteria, as well as THIS accidental discovery. While researching the bacteria Staphylococcus in 1928, Fleming left out cultures plates on a bench in his workshop over the weekend. When he returned, he observed that fungus had grown on the dish. In the areas close to the fungus, the bacteria had been eradicated! The mold led to the creation of the first antibiotic, Penicillin. Without Fleming’s mistake, the history of medicine in the last century would look very different and many who lived may have died instead.

The Byzantine Empire, the last remaining part of the Roman Empire, was getting pretty small by the 1450s, essentially consisting of a few islands and the capital of Constantinople. The city came under siege by the Ottoman Empire in 1453, which lasted for 53 days. Although the Ottomans’ superior numbers and cannons likely would have overcome Constantinople’s defenses eventually, it wouldn’t have fallen as quickly if not for someone leaving a small postern gate, called the Kerkoporta, unlocked. Fifty or so of the invaders were able to enter the city and raise their flag from the walls, sending the defenders into a panic and allowing the Ottomans to easily overpower them.

On June 6th, 1944, the Allies launched an ambitious operation to retake Western Europe. Known as D-Day, the first landings occurred on the beaches of Normandy, France. The casualties were high, but the operation granted the Allies a foothold that would eventually lead to victory on the Western Front. However, things could have gone very differently. The Germans’ most accomplished general, Erwin Rommel, was in charge of defending the Atlantic Wall against an invasion. However, he’d decided to take leave, as the 6th was his wife’s birthday, and German meteorologists had mistakenly predicted storms for another few weeks - making a seaborne invasion unlikely. Had Rommel been in command, the Allies may never have gotten a beachhead to retake France.

During the 19th century, the Crimean War caused several countries to begin exerting pressure on Russia through blockades of their sea routes. Because of this, they were unable to properly supply their largest overseas territory, Alaska. To offset this, in 1867 Russia sold the territory to the United States for 7.2 million dollars. While it may have been a smart move at the time for Russia, in retrospect, it’s often seen as a mistake, as the gold and oil discovered in Alaska far exceeds the value it sold for. Not only that, but Russia having a foothold in the North American continent would have caused the Cold War to play out very differently.

The Berlin Wall was a grim symbol of the divide between not only East and West Germany, but of the Iron Curtain; erected to stem the massive exodus from the communist controlled East to the democratic West. However, it all came crumbling down much faster than expected, thanks to an unprepared East German official. On November 9 1989, Günter Schabowski was handed a text about new travel allowances, but didn’t have time to review it before his press conference. Instead of telling people that East German citizens could apply to cross the border the following day, he said that people could cross immediately. This quickly led to thousands crowding the wall. Unwilling to open fire, border guards let them through, and the rest is history.

A British soldier’s choice to spare the future Fuhrer's life during WWI turned out to be a HUGE blunder. But we’d argue that the most dramatic mistake involving Adolf Hitler was one he made himself. Despite signing a non-aggression pact with Russia, Hitler still considered Joseph Stalin and the Soviet Union his enemies. In June of 1941, the Germans invaded Russia. Despite committing the largest invasion force in history, the Germans were unprepared for the Soviets’ scorched earth tactics or the bleak Russian winter, and they experienced over half a million casualties. The offensive split and depleted the German forces, and put Russia on the side of the Allies, which likely lost Hitler the war.

One of the most famous killings of all time, the assassination of Austro-Hungarian Archduke Franz Ferdinand is usually credited with being the catalyst for World War I. But what some may not know is that it could have been avoided, if not for a wrong turn. The archduke had already survived one assassination attempt with a bomb by the same group while visiting Sarajevo. On the return journey, the archduke’s drivers, who spoke Czech, couldn’t understand their directions for a new route, and took a wrong turn. When they stopped to reorient, it was right next to one of the assassins who promptly pulled out a gun and shot both Ferdinand and his wife.

In 1945, with Nazi Germany defeated, the Allies demanded the unconditional surrender of Japan. In a press conference, Japanese prime minister Suzuki Kantarō replied with a phrase containing the word “mokusatsu,” which can translate to “ignore”, or to “treat will silent contempt”. He added that Japan would continue to fight. While it was clear Japan couldn’t win the war, the military opposed complete disarmament, and the government wanted to secure assurances about the Emperor’s future. Suzuki’s comments may have been misinterpreted as more extreme than he intended; either way, the result of this conference was that the US dropped atomic bombs on Hiroshima and Nagasaki - killing up to 200,000 civilians.

Before we get to our top pick, here are a few honorable mentions:

The Dutch Didn’t Claim Australia
They Got There First, But the British Claimed It First

Victoria Hall Disaster
Yelling “Free Toys” to a Theater of Kids Caused a Stampede, But Led to Emergency Exits

NASA Ignored Warnings About the Challenger Disaster
Engineers Warned That It Was Unsafe to Launch the Space Shuttle

Mexico Attacked the Alamo
Santa Anna Making It an Example Only Further Inflamed the Texan Rebellion

Chernobyl Disaster
A Flawed Design & Breach of Safety Protocols Changed How We Perceive Nuclear Power

This Italian explorer was long portrayed as a hero, and the “discoverer” of the Americas. Nowadays, a lot more attention has been paid to his brutal treatment of indigenous peoples. But his most celebrated feat - sailing across the Atlantic Ocean in search of Asia - actually came about due to his mistaken belief that the Earth is a lot smaller than it really is. He arrived at this conclusion by using a mishmash of different estimates, as well as his own erroneous beliefs. If not for Spain’s dire need for spices, he probably never would’ve gotten a single ship, much less three.