50 Human Mistakes That Changed History FOREVER

50 Human Mistakes That Changed History Forever

Welcome to WatchMojo, and today we’re counting down our picks for the most influential blunders made throughout the entirety of human history.

Not Properly Prosecuting Donald Trump

Few people will disagree with the statement that Trump is one of the most divisive figures in human history. One of his major controversies was being found guilty on all counts in a New York trial, but he was never prosecuted for his crimes. Soon after the verdict in 2024, the Supreme Court said Trump and all presidents were immune from prosecution for their official acts. This decision became one of the most controversial in American history, with many critics claiming it makes the president above the law in the same way a king could be.

Leaded Gasoline

You don’t need a chemistry degree to know lead is pretty toxic to humans. This being common knowledge is a fairly new development, though, as it was a common petrol additive in the 20th century. In the 1920s, it was discovered that lead increased the performance of petrol. So, leaded petrol became the standard, and that remained the case for decades. It was only fully eliminated in 2021, according to the United Nations Environment Program. Its effects still linger, though, with tons of soil still being contaminated today. The decision becomes even more outrageous when you learn that people were concerned that lead was bad for us in the 1920s.

Africanized Bees in Brazil

Also called the killer bee, this insect was created by crossbreeding African honey bees with European ones. Scientists sought a resilient bee for tropical climates, that could produce honey as well as African bees, but were docile like European ones. It was created in Brazil in 1956, but a year later, 26 swarms escaped and interbred with bees across both North and South America. They’re exceptionally dangerous, mainly because if they feel threatened, they will attack in large swarms. They’re also an invasive species, hence why they’ve spread across two continents so quickly. At least they do produce a lot of honey, leading them to become the preferred species for commercial beekeeping in South and Central America.

Napoleon Mismanages Spain

Many people often ask the question, why would the French Emperor Napoleon make his brother, Joseph, the King of Spain? Joseph was hated by the Spanish, leading to a brutal guerrilla war that lasted almost 6 years. Napoleon referred to it as “The Spanish Ulcer”, alongside saying, “that unfortunate war destroyed me.” It split his forces across two fronts on opposite ends of the continent, and many historians believe it was unwinnable, unless Napoleon diverted all his resources and attention to it. Really, he should’ve left the Spanish Kings in charge; then Spain would’ve remained a loyal ally to Napoleon for a little while longer. It was a fairly strained relationship, though, with Spain mainly allying with France out of fear.

Californian Signal Flare

One of the worst wildfires in modern history began in California in October 2003, then lasted for 12 whole days. It was called the Cedar Fire, and was entirely caused by one man, Sergio Martinez. He had become lost while hunting, so he decided to light a signal fire, which spiralled out of hand. 280,278 acres were burned, and fifteen people tragically died. Martinez was charged for his crime, which resulted in him being given 40 days of community service, six months in a work-furlough program, five years of probation, and finally, he was forced to pay $9,000 in restitution. On the bright side, the area that was burned is beginning to thrive once again.

The Spanish Armada

Historians consider the British destruction of the Spanish Armada to be the first long-range naval battle in history. The Spanish plan was to fill a bunch of ships to the brim with men, then combine them with a few thousand more men in the Netherlands to invade England. In total, it was 16,000 Englishmen against roughly 55,000 Spanish. The Spanish plan was to board the opposing ships when they got close enough, letting their numbers overwhelm the English. It crumbled because the English ships were more maneuverable, so they decided to use long-range cannons to attack the Spanish. It worked wonders, especially since Spain only had short-range cannons. The weather also helped massively, but Spain’s strategic errors were the main reason it failed.

Gorbachev's Accidental Dissolving of the USSR

The Soviet Union’s final leader was Mikhail Gorbachev, who is often credited as the man responsible for its downfall. The country had been struggling, so Gorbachev tried to reform the USSR to avoid a collapse and end the Era of Stagnation. Sadly for Gorbachev, he got the opposite. Many of his reforms decentralized power and ended censorship. This led to many Soviet satellite states declaring independence, and then eventually the USSR collapsed entirely in 1991. To people who disliked the Soviet Union, it wasn’t a mistake by any means. To Gorbachev, who was trying his hardest to avoid a collapse, it was likely one of his most regrettable mistakes.

Wilhelm II's Naval Obsession

Following the Battle of Trafalgar in 1805, the British navy became the most powerful on Earth, and didn’t lose its status until well into the 20th century. Under the rule of Kaiser Wilhelm II, Germany decided it could be the one to challenge English naval dominance. During the years before World War 1, their navy was massively expanded. Wilhelm was successful in the sense that he did build a formidable fleet. Ultimately, it wasn’t strong enough to beat the Brits. In World War 1, only one naval battle was fought between the two powers - the Battle of Jutland. It was a stalemate, leading Germany not to bother beating Britain on the waves until the next war.

Thomas Austin's Rabbit Infestation

Rabbits are one of Australia’s most devastating pests. They’re an extremely invasive species that is nigh on impossible to control. For example, Australia built a massive rabbit-proof fence in the 1900s, which cost them a fortune and was widely considered a failure. If rabbits are so invasive, why would anyone import them in the first place? Well, a man named Thomas Austin brought them over in 1859, mainly so he could shoot them for fun. He brought 24 European rabbits across with him, and now, Australia’s wild rabbit population descends completely from Austin’s. Few humans have caused as much ecological damage as Austin did, and he likely never realised the harm he did before dying.

Titanic Locker Key

There were tons of mistakes that led to the failure of the allegedly unsinkable Titanic in 1912. Many people believe it may have never hit the iceberg if the lookouts had binoculars. David Blair was initially meant to be the ship’s Second Officer, but got reshuffled before her disastrous first journey. He took with him a locker key for the crow’s nest, which was believed to contain binoculars. It’s easy to pin the blame on Blair, but many experts assert that it wouldn’t have made a difference. Binoculars hamper your visibility on account of their small field of vision. As such, they were only used for figuring out something you’d already spotted, so it likely wouldn’t have made a difference.

Iraq Invasion Based on False Evidence

The Iraq War lasted 8 years, beginning after America’s invasion in 2003. One of its primary goals was to “disarm Iraq of WMDs.” Western intelligence found their leader, Saddam Hussein, was secretly constructing nuclear weapons. This turned out to be completely false, but when Iraq refused to let in a UN inspection, Western powers saw this as a sign their intelligence was correct. In reality, their nuclear programme had ended in 1991. Hussein was ousted, and while he was a pretty brutal dictator, the power vacuum he left behind caused a civil war and made things even more chaotic in Iraq.

Mismanaging Waterloo

After spending 11 months exiled on Elba, a tiny island off the coast of Italy, Napoleon Bonaparte sneaked to Paris, then reestablished the French Empire. It lasted 110 days before Napoleon was defeated at the Battle of Waterloo, and then exiled to the more remote Saint Helena. The battle was pretty catastrophic for the French, but many would argue that a much younger Napoleon could’ve easily won it. Sadly for the Bonapartists, his older self made a bunch of mistakes at Waterloo. For instance, he left one of his greatest commanders, Louis-Nicolas Davout, behind in Paris. If he’d won this battle and the war, then the French Empire would have been around significantly longer, but at this point, it was likely doomed.

Splitting Rome In Two

If you ask historians when Rome fell, you’ll likely be given a ton of different answers, ranging from 476 to 1453. The date the Empire split in two is much clearer: 395 AD. They believed it would be easier to defend if they separated into a Western and Eastern state. It turned out to be a pretty contentious idea: the East had all the wealthy provinces, like Egypt, while the West faced constant invasions along its lengthy borders. You could argue that the split saved the ERE, which existed for a thousand more years. They also owned parts of Italy until the Norman conquests of the 11th century. So, in a sense, the Western Empire still existed, but not like before.

Balfour Declaration

A lot of modern conflicts in the Middle East can be traced back to the Balfour Declaration of 1917. It established a “natural home for the Jewish people” in the Ottoman region of Palestine. It’s mainly criticised for showing little regard for the native Palestinians. Additionally, in the McMahon-Hussein correspondence in 1915, the British government promised independence to Arabs in the region. Quite a few historians believe it was driven by Britain’s desire to control both the Suez Canal and the Middle East, rather than genuine care for the locals. They also specifically used the term “national home,” an intentionally vague statement that arguably led to the Nakba in 1948, an ongoing ethnic cleansing of Palestinian Arabs.

Free Toys Led to Deaths & Emergency Exits

It’s pretty easy to take emergency exits for granted, but they’re a modern invention. Tragically, we wouldn’t realise their necessity until the horrific Victoria Hall disaster. In 1883, a variety show in Northern England promised children free toys. This led to a frantic rush of hundreds of children, who became bottlenecked by a door, bolted so only a small gap was left to pass through. 183 children died in the crowd crush that followed. In the aftermath of the catastrophe, it became the law for all entertainment venues to have emergency exits. Without it, we may not have push bar emergency doors, which have prevented similar disasters from occurring since.

Flight to Varennes

The French Revolution began in 1789, which led to the monarchy’s control hanging in the balance. That was until it went straight out the window in 1791, when King Louis XVI and his family tried to flee Paris. This destroyed the monarchy’s credibility, revealing that they didn’t care about cooperating with revolutionaries. It made the public much more supportive of a republic, alongside leading to Louis’ execution in 1793. Not only was it a bad idea, but the execution was diabolical. They rode in an easily recognizable heavy carriage, they were constantly delayed, and once they arrived at Varennes, the king was recognised from his portrait on their money. He was then arrested and sent back to Paris.

The Treaty of Taipei's Ambiguity

Imperial Japan ruled over Taiwan for 50 years, until its surrender at the end of World War 2. In 1952, the Treaty of Taipei was signed, which formally handed over Taiwan to China. The only problem was that, at that time, there were two rival Chinese governments. One was the Communist People’s Republic of China, then led by Mao Zedong. Rivalling them was the Republic of China, led by Chiang Kai-shek, who fled to Taiwan in 1949. The ambiguity of the treaty has led to decades of tensions between the two governments, with Taiwan’s sovereignty still a major issue in global geopolitics.

Death of Princess Charlotte of Wales

King George III was one of Britain’s most mentally unwell rulers. He was expected to be succeeded by George IV, then his only legitimate heir, Princess Charlotte, but sadly the latter died years before the former two. She died in childbirth aged 21 in 1817. After being in labor for 50-hours, her child was stillborn, and then she passed away shortly after. Many people criticised her physician, Sir Richard Croft, as he didn’t use instruments in delivering the baby. Quite a lot of people called this a grave mistake and believe that they have survived. Many historians disagree, however, instead claiming that her death was unavoidable. It had a massive influence on obstetrics, though, motivating future doctors to use tools more often.

Hindenburg

While the image of our skies being full of zeppelins sounds like a steampunk utopia, there’s a good reason this isn’t the world we live in. Lead airships became popular in the early 1900s, but the era ended after the Hindenburg disaster in 1937. The airship was full of hydrogen, a gas so light it allowed flight. Unfortunately, it was also extremely flammable. This resulted in the Hindenburg catching fire in New Jersey, causing the deaths of 36 individuals. It wasn’t the deadliest airship crash in history, but it was heavily documented, making public opinion overwhelmingly opposed to zeppelins.

Tiananmen Square Crackdown

Unlike the reforms made by Gorbachev in the 80s, Chinese leader Deng Xiaoping’s reforms did not lead to a collapse of Communist China. This is because Deng prioritized liberal economic changes, but still ruled with an iron fist. During the 80s, China’s New Enlightenment era blossomed. This culminated in the Tiananmen Square protests in 1989, which called for things such as democracy and freedom in China. When the protests didn’t naturally subside, the CCP declared martial law and sent the military to forcibly remove the protestors. Hundreds died, and the event has since been massively censored by the CCP. This means quite a lot of younger Chinese people won’t ever hear about it until they leave the country.

France’s Maginot Line

After World War I, France was understandably anxious about a second German invasion. This led them to fortify the French-German border, which became known as the Maginot Line. It was a huge strategic blunder, since Germany decided to simply walk around it. This allowed them to invade France in less than two months, also due to brutally efficient blitzkrieg tactics. Germany had already invaded through the Low Countries in World War 1, so their plan could’ve been predicted. It also expected World War I-era trench warfare, when in reality, warfare had changed significantly. It cost France billions, convincing many that it was a major factor in Germany’s initial wartime success.

Alexander the Great Leaves No Heir

When it came to carving out an empire, Alexander was unsurprisingly great at it. He was the King of Macedon, who extended his kingdom from Greece to India. After mysteriously dying at the young age of 32, no one could agree on who would inherit his empire. This led to the Wars of the Diadochi, where his generals fought for control for 41 years. In the end, it was split into multiple rival states. They would ultimately decline due to infighting, paving the way for Roman conquests. The longest-lasting one was the Ptolemaic Kingdom, which ruled Egypt until the Roman invasion in 30 BC.

Hiring Anglo-Saxons

Take this next entry with a grain of salt, as it comes from a period particularly lacking in sources. While the Western Roman Empire was crumbling in the 5th century, it supposedly hired Anglo-Saxons to defend the nation. Their threats were mainly Picts, Scots, and Saxon pirates. When Rome wouldn’t help, an unnamed Romano-British tyrant enlisted Saxons for help in the 440s. This tenuous alliance supposedly went south when they weren’t properly supplied. The Britons rallied to a new leader, Ambrosius Aurelianus. Eventually, in 500, the Britons were successful at a monumental battle. The only sources we have for this lived decades after these events, making their authenticity questionable.

Remaining Idle After Lehman Brothers Files for Bankruptcy

The 2008 financial crisis was a major economic stressor, affecting the entire globe. One contributing factor was the Lehman Brothers’ bankruptcy. They held over $600 billion in assets, making it the largest bankruptcy filing in American history. Importantly, the U.S. government chose not to bail them out. It triggered a domino effect, banks stopped lending, markets crashed, and then entire financial systems collapsed. Millions of people lost their jobs due to the economic crisis. It was part of the larger Great Recession, which caused huge GDP declines in the Western world. Many economists believe a controlled bailout of Lehman Brothers could have prevented the panic.

Exxon Valdez Oil Spill

In 1989, the Exxon Valdez oil supertanker hit a reef off the coast of Alaska. This caused a monumental disaster, spilling over 10 million gallons of oil into Alaska’s Prince William Sound. Over 1,300 miles of shoreline were devastated. Estimates say over 250,000 seabirds were killed, alongside 2,800 otters, and billions of salmon and herring eggs, among other species. It was extremely difficult to clean, since the Prince William Sound isn’t easily accessible. Exxon spent more than $3.8 billion in cleanup costs, but the effects still linger today and are likely to persist for decades.

Engineers Working in Inches

Among the scientific community, imperial units are often considered a joke, only really used by the United States. Compared to the metric system, it’s a headache to convert between units. This difference in units eventually led to disaster in 1999. NASA tried to launch a $125 million orbiter to probe Mars, but the engineers at Lockheed Martin used imperial units. Everyone else involved used metric, the default among scientists. The error caused the probe to be permanently lost when entering Mars’ orbit. In the end, NASA blamed itself for the miscommunication, rather than the engineers.

The Battle of Teutoburg Forest

Our next entry is one of the most important disasters in Roman history. On September 9th, 9 AD, Roman general Publius Varus led three legions straight into a trap by the Germanic peoples. They were led by a Roman-trained chieftain, Arminius. This marked the end of Augustus’ outward expansions. It happened near the Rhine River, which made this Rome’s permanent boundary with Germany. Had Rome conquered Germania, it may have expanded the Latin language deeper into Europe. Germanic tribes developed independently, and later played major roles in the Western Empire’s collapse. Alternatively, it could have caused Rome to overexpand harder, thus triggering an earlier fall.

Japan Screws Up Pearl Harbor

In December 1941, Japan launched a surprise attack on Pearl Harbor, an American naval base in Hawaii. Their main goals were to neutralize America’s fleet, buy time to conquer territories like the Dutch East Indies, and then to finally shock them into a peace deal. This was because Japan knew they couldn’t win a prolonged war. The attack had the opposite effect; it unified a divided America, which soon entered the global conflict. It also missed key targets, like aircraft carriers, fuel depots, and repair yards. The Navy recovered quickly, then went on to ultimately destroy the Japanese Empire once and for all.

The Fourth Crusade

The goal of the Fourth Crusade was to reach the Holy Land and recapture Jerusalem from the Ayyubid Sultanate. Instead, they besieged the Catholic city of Zara in 1202. Then, they went on to get mixed up in a Byzantine succession crisis, which didn’t go their way. In response, they destroyed its capital, Constantinople, the heart of Eastern Orthodox Christianity. It’s widely regarded as the most catastrophic of all the crusades, which were all fairly chaotic. It didn’t even reach the Holy Land, destroyed a Christian city, then fatally weakened the only Christian empire standing between Europe and Islam. This Empire fell to the Ottomans, meaning the crusaders only worsened the issues they sought to solve.

Burning of Baghdad

For most of the Medieval period, Baghdad was one of the greatest cities in the world. That was until 1258, when it was destroyed by the Mongols. Genghis Khan’s grandson, Hulegu, had an army 138,000 men strong, which he used to pacify Persia. It was catastrophic for the Persians, with their capital, Baghdad, getting decimated. It was the heart of Islam’s Golden Age, home to thousands of scholars, scientists, artists, and philosophers. The Mongols burned libraries, killed scholars, and destroyed centuries of information. We’ll never truly know how much was lost, but we’ll always remember it as one of humanity’s greatest tragedies.

Kim Jong-nam Goes to Disneyland

Kim Jong-nam was once the heir to the North Korean dictatorship, until 2001 when he made an embarrassing attempt to visit Tokyo Disneyland. Traveling on a fake Dominican Republic passport bearing a Chinese name, Kim was arrested upon arrival in Japan and deported to China. The incident deeply embarrassed his father, Kim Jong Il, and caused him to be shunned by his family. Ultimately, his younger half-brother, Kim Jong Un, took over from their father. In 2017, Kim was assassinated in Malaysia, and it was later revealed that he had been a CIA informant. He also supported reform and free market policies, which apparently contributed to him being passed over. Had he never attempted that fateful trip, perhaps North Korea’s trajectory might have been different.

Byzantine Refusal to Hire Urban

The Roman Empire’s final two centuries were their most difficult. By 1452, the Ottoman Empire already had its eyes on Constantinople, which prompted Hungarian siege engineer Orban to offer his cannons to the Romans. Unfortunately, they couldn’t afford his services or provide the materials needed to construct his weapons. So Orban took his business to the Ottomans, who happily took him on. He crafted the basilic, one of the largest cannons in history, requiring 90 oxen and 400 men to transport it. Its cannonballs, each weighing 1200 pounds, devastated the Theodosian Walls, which were impenetrable for about 800 years prior. The Ottoman Sultan also carried warships across the land, bypassing the harbor’s great chain, and giving them another huge advantage.

Titanic Sinks After Iceberg Warnings Are Ignored

Many mistakes were made that caused the Titanic to sink, so it’s difficult to pinpoint just one. Perhaps the most consequential, though, was turning “hard-a-starboard” when they spotted the iceberg, which extended the collision, creating a large gash that flooded five compartments. Had they struck the iceberg head-on, the bow would have been crushed, but only one or two compartments would have flooded. In such an event, the ship could have survived, as it was built to still float with up to four flooded compartments. Also, it carried only 20 lifeboats, enough for about half the passengers. The primary mistake that night was ignoring iceberg warnings and maintaining a high speed throughout. Changing just this one decision could likely have prevented the accident.

Mexico Attacks the Alamo

In 1836, the Texas Revolution was underway, with the Anglo-American residents of Texas fighting for independence from the Mexican Republic. They were successful, winning 10 years of independence before joining the United States in 1846. During the war, Mexican forces under General Antonio López de Santa Anna laid siege to the Alamo. After 13 days, roughly 1,500 Mexican soldiers launched a decisive attack, overwhelming the garrison of about 200 Texians after three attempts. It was a pyrrhic victory though, as the merciless bloodshed inspired many to join the Army, hoping to take revenge for the loss of their fellow Texians. Mere weeks later, a now fortified Texian army attacked the Mexicans by surprise in the Battle of San Jacinto, decimating them in just 18 minutes.

Trojans Bringing in the Horse

This was a mistake so monumental, it became a metaphor for deception that is still widely used today. The ancient city of Troy was first destroyed around 1200 BC, and again by archaeologist Heinrich Schliemann in the 19th century. According to legend, the Greeks built a giant wooden horse, hid soldiers in it, and presented it to the Trojans as a gift. Believing it to be a symbol of victory, the Trojans brought it into their city, only for Greek soldiers to emerge and decimate Troy. The tale’s authenticity remains heavily debated, with no direct evidence. However, oral history played a central role in the ancient world, which preserved surprisingly truthful elements, suggesting that this tale may have been inspired by real-life events.

Caesar Ignores Warnings

Julius Caesar is most famous for sowing the seeds of the Roman Empire, enslaving and slaughtering millions of Gauls, and giving the month of July its name. He was eventually assassinated in 44 BC, which shouldn’t have come as a surprise, since he was given several warnings about it. All of these were dismissed, leading to his death in the Senate, where he was stabbed 23 times. A soothsayer warned him to beware the Ides of March, the eventual date he was killed. His wife Calpurnia had a dream of his death, and insisted he stayed home, but he dismissed her fears. Ultimately, his trusted friend, Brutus, convinced him to come in, which turned out to be the dictator’s final mistake.

Mao’s Great Leap Forward

Mao Zedong was the founder of Communist China, who became leader of the CCP during the Long March, a pivotal event in the Second Sino-Japanese War. After Japan’s defeat, he sought to industrialize China, and finally recover from the century of humiliation. He believed rapid industrialization would help them catch up to the West, but it turned into a catastrophic failure. The plan was overly optimistic, and resulted in mass famine and economic collapse. By 1962, Mao faced criticism for his policies and was sidelined at the Seven Thousand Cadres Conference. This didn’t last long though, as just four years later, he kickstarted the Cultural Revolution, which allowed him to reclaim full control of the nation.

NASA Ignored Warnings

In 1986, NASA launched the shuttle Challenger, which tragically exploded only 73 seconds after liftoff. The event occurred during a cold morning, which caused the ship’s rubber O-rings to stiffen, leading to a fuel leak that ignited the vessel. All seven crew members perished, marking one of the darkest moments in the history of space exploration. Months earlier, several engineers, including Roger Boisjoly, had warned of an impending failure due to the O-rings’ vulnerability to cold. Boisjoly even wrote a memo outlining this issue, but his concerns were completely ignored. Although a team was formed to address the problem, they lacked adequate support, and the launch proceeded only to end disastrously, like Boisjoly predicted.

America Escalating Tensions in Vietnam

The United States entered the Vietnam War following the Gulf of Tonkin incident, where North Vietnamese forces allegedly attacked the U.S. Navy in international waters. The event was framed as an unprovoked attack, but later evidence showed otherwise. While the first attack remains debated, the second one was entirely fabricated. It devolved into a brutal war, which dragged on for years, causing thousands of American and Vietnamese deaths. Along the way, the United States committed atrocious war crimes, such as the My Lai Massacre. Ultimately, the war ended in failure, all spurred by an incident with very little evidence.

Angering Genghis Khan

Many words can be used to describe Genghis Khan, one of history's most successful conquerors, but “cool-headed” isn’t one of them. In less than two years, Genghis annihilated the Khwarazmian Empire. While there were a variety of factors that contributed to this invasion, the main one was an insult to his ambassadors. In 1218, the Khan sent a caravan to the Empire, who were arrested and executed, on suspicion of being spies. When Genghis sent diplomats to deal with the situation, the Khwarazmians refused to comply and beheaded the chief envoy. By 1221, their empire was shattered, and they had suffered somewhere between two and 15 million casualties. Maybe think twice before you insult one of history’s most ambitious conquerors.

Fleming Discovers Penicillin

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 culture 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.

Bay of Pigs Failure

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.

Chernobyl Nuclear Disaster

Chernobyl’s meltdown was the most destructive nuclear disaster in history, and could have been completely avoided if the proper procedures were followed. The disaster was immediately caused by a safety test, which was meant to be carried out during the day, with a trained crew. Instead, the untrained night crew did the test, with very little time to prepare for and properly carry it out. The Soviets were also secret about their nuclear technology, withholding important information from operators and engineers, who should have understood them. After the explosion, further mistakes were made, like the nearby town of Pripyat not being evacuated until over a full day later. It was the perfect storm of mistakes, leading to one of humanity’s worst disasters.

B-Day Lost D-Day

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.

Russia Selling Alaska

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.

Napoleon Invades Russia

In 1812, Napoleon famously declared war on Russia, citing their refusal to comply with the Continental System. He brought around half a million soldiers from all across Europe to the border, and proceeded to march them to Moscow. The Russian defense was confused, with no planned resistance, with their eventual scorched earth tactic being largely improvised. At the Battle of Borodino, Napoleon abandoned his usual cunning tactics and ordered a direct assault instead. The French won and Moscow was taken, but Little Boney never received the peace deal he expected. Eventually winter took hold, and Napoleon embarked upon one of history’s most disastrous retreats, costing him his army and, ultimately, his empire.

Hitler Invades Russia

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.

Wrong Turn Starts WW1

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.

Treaty of Versailles’ Harsh Terms

The Treaty of Versailles was a deal signed in 1919 at the end of World War 1, which mainly focused on weakening the German Empire. Despite the Austrian-Hungarian Empire being the main instigators, sending a harsh ultimatum to Serbia, the victorious powers primarily blamed Germany. They had to accept full responsibility for starting the war, and were made to pay enormous reparations. This crippled their economy, and fostered resentment towards the victorious powers, which eventually led to Hitler’s rise to power, and World War 2. If the Allies had adopted a less punitive approach, like the U.S. did to Japan after World War 2, the devastating second war, and the rise of Nazi Germany, might have been alternate history.

Columbus Sailing to India

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.

What historical mistake do you think had the most profound consequences, and was it mentioned today? Let us know in the comments below!