The “Phoney War” was an eight‑month build-up to war

Germany’s invasion of Poland in 1939 launched World War II

On September 1, 1939, Nazi Germany launched a surprise invasion of Poland using blitzkrieg—coordinated air bombardments and armored assaults—to overwhelm Polish defenses within weeks. This lightning-strike strategy shocked the world and signaled both the start of World War II and a revolutionary shift in modern military tactics.

European leaders pursued appeasement of Hitler in the 1930s

In the 1930s, Britain sought to maintain peace by ceding territory to Nazi Germany, most notably via the 1938 Munich Agreement allowing Germany to annex the Sudetenland. These concessions, seen as pragmatic amid anti‑war sentiment, ultimately failed to curb Hitler’s aggression and directly contributed to the outbreak of World War II.

Before Pearl Harbor, the US was a nonbelligerent ally to the Allied powers

Between September 1940 and December 7, 1941, the United States remained officially neutral—yet President Roosevelt incrementally shifted policy from “cash‑and‑carry” to Lend‑Lease, funneling critical military aid to Britain and other allies without entering the war.

'Keep Calm and Carry On' was long-forgotten World War II propaganda

The British Ministry of Information developed the stoic phrase ahead of German attacks at the start of World War II in 1939. It was never officially released on posters and then lay dormant until 2000, when one of the remaining posters was discovered at a bookstore in the UK. It has since been adapted into countless memes.

A 1983 NATO war simulation provoked the Soviets to prepare for war

The "SNAFU" podcast, hosted by actor and comedian Ed Helms, explores some of the biggest blunders in history. Season one focuses on the 1983 NATO Able Archer military exercise, a war game that simulated nuclear attacks on the Soviet Union. The USSR mistook the exercise for a genuine threat and prepared its forces for war. Helms recounts this almost catastrophic event in world history with his signature humor.

The treaty that ended the First World War laid the groundwork for the Second

On June 28, 1919, the Treaty of Versailles officially ended World War I by demanding severe reparations, territorial losses, military restrictions, and the infamous “war guilt clause” against Germany. However, its harsh terms fostered deep resentment, economic instability, and political turmoil—ultimately becoming a catalyst for World War II.

Governments have historically used counterfeiting for economic warfare

Inserting fake currency into an economy can help destabilize it. During the American Revolution, for instance, the British distributed counterfeit “Continental Dollars” in an effort to devalue the currency being used in the US at the time with the goal of undermining America’s growing financial credibility. The Nazis also ran an extensive counterfeiting scheme during WWII.

World War II helped convince food companies to produce more processed foods

Processed foods had existed since the 19th century, but they began infiltrating the mainstream during World War II, with foods designed to last on the battlefield for days. After the war, food companies saw great potential in the relatively cheap foods aimed at busy households. (Some readers may experience a paywall.)

The first test of America's war powers came just a decade after the Constitution was ratified

During the undeclared Quasi-War with France in 1800, the Supreme Court ruled in Bas v. Tingy that Congress had authorized a valid "imperfect war" through statutes alone, without a formal declaration, establishing that there is a legal spectrum between peace and declared war.

In 1914, the Financial Times asked readers to redraw Europe for cash prizes

Two months in World War I, the newspaper invited readers to sketch postwar borders and submit peace terms for cash prizes. The contest captured public attempts to predict a new world order and foreshadowed modern crowdsourced forecasting. It's a wild look at how uncertain Europe's future was at the time.

In 1938, 1.7 million people were fooled into believing a Martian invasion was underway because of a radio play

Orson Welles' realistic radio dramatization of a Martian invasion of Earth, called "The War of the Worlds," caused quite a stir with audiences. The broadcast resulted in panic, with some people in the area where the story took place attempting to flee. It also helped Welles secure a contract with a Hollywood studio, leading to the creation of "Citizen Kane."

In the 1980s, excerpts from fake diaries of Adolf Hitler were published in a prominent German magazine

Excerpts from the diaries were published in other publications around the world, like The Sunday Times, despite uncertainty about their authenticity. After forensic analysis, the diaries were proven to be fake. The diaries were produced by Konrad Kujau, a petty criminal who frequently produced counterfeits.

The Cold War (1947-1991) prompted the birth of NATO and the Soviet Warsaw Pact

The geopolitical rivalry between the United States and Soviet Union was considered “cold" because the two countries never directly engaged in military combat during the time period. This page from the Kennedy Presidential Library outlines the causes and major events of the early Cold War.

Manhattan Project explained

Driven by fears of a Nazi nuclear bomb, the Manhattan Project united leading scientists to build the first atomic weapons. Its success ended World War II, caused catastrophic human loss, and launched the nuclear age that reshaped global politics and science.

Radar saved the British Royal Air Force from Nazi air assaults

Radar technology—particularly the Chain Home early-warning system—enabled the RAF to detect incoming Luftwaffe raids up to 80 miles out, coordinate fighter deployments through the Dowding System, and achieve interception rates over 90%. This technological edge was pivotal in winning the Battle of Britain and halting Germany's air campaign.

The 1967 war was the first use of oil as a geopolitical weapon

Following the June 1967 Arab–Israeli war, Saudi Arabia, Kuwait, Iraq, Libya, and Algeria embargoed oil shipments to the US, UK, and West Germany. While the move did not have a large impact, it reshaped global oil flows, and foreshadowed OAPEC's later actions.

Jean-Paul Sartre worked on 'Being and Nothingness' while a prisoner of war

The Nazis invaded France in May 1940. Sartre, as a member of the French Army, was taken prisoner that June. While he was in captivity, he studied Martin Heidegger and worked on "Being and Nothingness," one of his most famous philosophical works.

Jacqueline Jenkins-Nye—Bill Nye's mother—worked as a code-breaker in World War II

While in the Navy, she was recruited to work on Enigma to help decode messages from the German military. Historians estimate that the efforts of code-breakers may have collectively shortened the war by as much as two years.

Clue, the murder-mystery board game, was designed during World War II air raids.

Lego stop motion reenacts the longest battle in World War I

One of the longest and bloodiest battles of World War I, the Battler of Verdun was a deadly conflict between French and German forces for 10 months in 1916. Some 300,000 lives were lost, but ultimately the French triumphed. This video provides a stop-motion reenactment of the battle in Lego bricks.

The second attack used to justify full-scale US involvement in Vietnam never happened as reported

In August 1964, Washington claimed that North Vietnam launched two attacks on US destroyers in the Gulf of Tonkin. The second, used to justify escalating the US war effort, was later revealed to most likely have been a radar mistake.

The modern Olympic truce originated in a real pause in ancient conflict

Back in Ancient Greece, neighboring city-states were constantly at war. So when the Olympics started in 776 BCE, they needed a way to keep the peace. This video from the International Olympic Committee discusses the origins of the Olympic Truce and its reinstatement at the 1994 Games in Lillehammer.

Oktoberfest has been canceled 26 times

The first time, in 1813, Bavaria was fighting off Napoleon’s army, which left little time for celebration. Years were also lost to the Austro-Prussian War, a worldwide cholera outbreak, and both World Wars. Most recently, the 2020 and 2021 Oktoberfests were canceled due to COVID-19.

The word ‘fantasy’ wasn't used to describe the genre until the 20th century

The word—at least as a word used to describe fiction—didn’t appear in the Oxford English Dictionary until 1949. Scholars believe that’s due to the arrival of the Magazine of Fantasy and Science Fiction, an influential publication, and the rise in fantasy’s popularity following World War II.

Spielberg improvised most of the iconic D-Day scene from 'Saving Private Ryan'

Although action sequences are often tightly choreographed, one of cinema's most famous war scenes was mostly shot on the fly. Spielberg wrote seven pages (or approximately seven minutes of screen time) for the scene, though the final cut of the sequence was 25 minutes long.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

American dance legend Martha Graham, sometimes called 'the Picasso of dance,' refused to perform at the 1936 Olympics in Berlin and conceived the piece 'Chronicle' in response to the experience.

The Russia-Ukraine conflict is the largest ground war in Europe since World War II in casualties, forces mobilized, and displacement of civilians.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

The Beatles' US label rejected the band's first two singles, 'Please Please Me' and 'From Me to You,' with one executive calling the band 'dead in the water.'

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

Doctors differentiate between a phobia and fear by asking patients whether their fear interferes with their day-to-day activities.

Famed poet TS Eliot rejected the manuscript for George Orwell's political fable 'Animal Farm,' writing that its criticism of authoritarianism was not 'the right point of view.'

Volcanic activity may have triggered the Black Death by spewing gases that led to crop failures in Europe, thus forcing the import of grain ships with plague-infested fleas.

The first horror movie is believed to be George Méliès' 1986 short 'The Haunted Castle,' which pioneered the use of special effects

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

During the French Revolution, a botanist's letter asking about "dear Rhus" (poison ivy) was intercepted, leading authorities to suspect he was conspiring with the Russians.

Trace how the Bill of Rights, inspired by centuries of political theory, took shape between 1774 and 1789.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

Elk Cloner, the first computer virus to spread in public, was written as a practical joke by Richard Skrenta, a Pittsburgh high school student.

See the most iconic photos from four decades of LIFE magazine

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

The word 'jazz' evolved from 'jasm,' 19th-century American slang for 'energy'

An initial public offering or 'IPO' is the process of a private company becoming public by putting shares of the company on the stock market for purchase.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.