10 Worst Risks in History That Almost Ruined Everything

Welcome to WatchMojo, today we’re looking at perilous gambles in history which almost completely backfired. For this list, ‘everything’ doesn’t necessarily mean the whole world, but everything from the risk taker’s perspective.

Black Saturday

The Cuban Missile Crisis was perhaps the closest humans have come to mutually assured destruction. In 1962, the Cold War between America and the Soviets peaked. America placed nukes in Turkey and Italy, motivating the Soviets to put their own in Cuba. This turned into a Caribbean standoff. On “Black Saturday,” the US Navy accidentally dropped practice depth charges on a Soviet nuclear submarine, without telling them. The submarine nearly retaliated by launching their nukes, but thankfully one commander refused to give his consent. The whole crisis was an enormous risk that almost wiped out humanity.

Nuclear Bombs in Korea

In 1950, the Korean War began, a proxy war between both sides of the Cold War. The North was Communist, the South Capitalist. Douglas MacArthur was one of the most famous American generals in history, and he was a major player in the war. It wasn’t as easy to win as they expected, and in 1951, MacArthur was nearly authorized to use nuclear weapons on China. Thankfully the Atomic Energy Commission didn’t like this idea, and refused to give MacArthur this power. Truman preferred a less aggressive approach, and eventually relieved him from command to avoid nuclear war with China.

Heraclius[a]’ Reign

Heraclius came to power after an extremely risky revolt against Phocas in 610, a widely hated ruler. If failed, he would’ve been executed without a second thought - but he managed it. The Roman Empire was on life support at this point. By 627, the Sasanian Empire had captured Egypt, Syria, and most of Anatolia. Instead of surrendering, Heraclius bet everything on a counter-offensive. He restructured the economy, and personally led his army deep into Persia. If he had failed, the Roman Empire would have been annihilated from history. The Battle of Nineveh in 627 brought him a decisive victory against the Sasanians. Without his actions, they might have fallen to the Sasanians, or been unable to completely resist the Arab conquests in the 630s.

The Tet Offensive

Now for a textbook example of a massive miscalculation. In 1968, during the brutal Vietnam War, the North Vietnamese launched a surprise attack on the South. It was a military defeat for the North, with most attacks being repelled. Still, its consequences were devastating. It revealed to the US public just how unwinnable the war was. In 1967, General Westmoreland famously declared they could see “light at the end of the tunnel.” This coordinated offensive from the Communists showed how false this claim was. Support for the war plummeted, President Johnson was humiliated, and the US would eventually leave in the early 70s.

Caesar Crossing the Rubicon[b]

Now for a move so risky, it became an idiom. The Rubicon River was the boundary between Gaul and Italy, and Caesar's crossing was considered treason, since a general was forbidden from bringing legions into Roman territory without the Senate’s approval. This was an act of civil war, and if defeated, he would have been executed and his entire faction destroyed. The Roman Republic was in a fragile state, and Caesar was heavily outnumbered. A defeat would have caused further unrest, but he emerged victorious, marking the end of the Republic. He would eventually be killed by the Senate, but his heir Augustus finished what he started, and Rome entered a golden age.

The Penkovsky False Warning

Colonel Oleg Penkovsky[c] was a Cold War double agent. A lot of people credit him for defusing the Cuban Missile Crisis by providing the US with Soviet information. In 1962, he also sent a warning to Western intelligence agencies that the Soviet Union was about to launch a nuclear strike. He made these calls after the crisis ended; one was received by the CIA, the other by MI6. Both recipients believed the information wasn’t genuine and decided to do nothing. This was an immense risk, since if it had been true, Europe and the US would have been annihilated. Thankfully, their instincts were correct, and nuclear war was averted.

The Battle of Cannae[d]

Hannibal Barca was one of Rome’s greatest enemies. He was a Carthaginian general whose father made him swear to destroy Rome. In 218 BC, he began the Second Punic War, crossing the Alps on elephants. This extreme risk nearly cost him his army, but once he made it into Italy, he quickly allied with local Gallic tribes, who hated Rome. This helped him achieve multiple crushing defeats against the Romans. Most notable was at Cannae, when the Senate sent around 86,000 soldiers to fight Hannibal. He executed a double envelopment tactic, and this cunning maneuver resulted in 50,000-70,000 being slaughtered in a day. Rome’s decision to fight Hannibal nearly cost them their republic, motivating their later decision to avoid fighting Hannibal at all costs.

1983 Soviet False Alarm

Returning to the Cold War, in 1983 humanity had another near miss with mutually assured destruction. In September, the Soviet warning system alerted them about five American ICBMs. Engineer Stanislav Petrov[e] found it suspicious, especially since only five nukes were launched - nowhere near enough to destroy the USSR. Rather than relay the warning, he decided to wait for confirmation. None came, because it was a malfunction. The missiles were just sunlight. If Petrov had relayed the message, then a counterattack would have developed into a full-scale nuclear war. Unfortunately, Petrov wasn’t rewarded for his bravery, since officials were embarrassed about the false positive.

The Battle of Manzikert[f]

The Eastern Roman Empire experienced a golden age during the medieval period, but its decline began in 1025, after the death of Basil II. Chaos reached an all-time high in 1071, in the aftermath of Manzikert. This battle between the Romans and the Seljuks resulted in an overwhelming defeat, with many Roman forces including Turkic mercenaries in their ranks. Many refused to fight, or even defected, and the Seljuk Empire gained almost complete control over Anatolia. This almost destroyed their empire, but in 1081, Alexios Komnenos took the throne. He spent his reign dealing with crisis after crisis, and after almost 40 years on the throne, the Roman Empire was stable once again.

Operation Overlord

The Normandy landings were the largest seaborne in military history. France was firmly under German control until June 1944, when nearly 160,000 Allied troops crossed the channel. By summer’s close, more than two million Allied soldiers were in France. Its success was vital to toppling Hitler’s regime, but was far from guaranteed. A failure would have prolonged the war, giving the Nazis a stronger hold on Europe. The Nazis would have strengthened their defenses, and a second invasion may have never succeeded. Thankfully the risk paid off, and within weeks Paris and later France were liberated.

What do you think was the most precarious gamble in history? Leave it in the comments section!

[a]hair-uh-CLY-uss / hera-CLY-iss https://www.merriam-webster.com/dictionary/Heraclius

Phocas = basically focus
suh-SANEY-in https://www.merriam-webster.com/dictionary/sasanian
NINNA-vuh https://www.merriam-webster.com/dictionary/Nineveh
[b]RUBIK-con https://www.merriam-webster.com/dictionary/Rubicon
[c]OH-leg pen-KOFF-skee https://youtu.be/POU99ef_zSI?si=3fSp6itVeYPXFfeS&t=621
MI6 = em eye six
[d]can-eye https://youtu.be/v_i2RLY91d0?si=a19jxDQlmc5vGZkc&t=4
https://youtu.be/hfIe9P13X8s?si=1OeM6zxr6PWmHSxw&t=241
https://youtu.be/3623pilC2_s?si=LP1TxodsKMW2dPuP&t=16
Barca = BAR-kuh
cartha-JINNY-in https://forvo.com/search/Carthaginian/
PYEW-nick https://forvo.com/search/Punic/
GAL-ick https://forvo.com/search/Gallic/
[e]stannis-slav PET-rov https://translate.google.ca/?sl=ru&tl=en&text=%D0%A1%D1%82%D0%B0%D0%BD%D0%B8%D1%81%D0%BB%D0%B0%CC%81%D0%B2%20%D0%9F%D0%B5%D1%82%D1%80%D0%BE%CC%81%D0%B2&op=translate
[f]MAN-ZICK-kurt https://forvo.com/search/Manzikert/ https://youtu.be/wHwoD5Q_1SY?si=6CYgcYJXnarj8mqB&t=64
Basil II = bazzle the second
SELL-jooks https://www.merriam-webster.com/dictionary/seljuks
ah-LECKSY-oce comb-NEN-noce https://forvo.com/search/%CE%91%CE%BB%CE%AD%CE%BE%CE%B9%CE%BF%CF%82%20%CE%9A%CE%BF%CE%BC%CE%BD%CE%B7%CE%BD%CF%8C%CF%82/ OR https://youtu.be/b9dyV7XUfCA?si=cXgaGIzBmyKFZ6O9&t=56 (british ppl pronounce "-os" at the end of words differently, but it should rhyme with "dose")