The US gave Iran its first nuclear reactor in 1967, fueled with weapons-grade uranium, on a campus that later hosted weekly 'Death to America' chants.

Just a year after the revolution, Saddam Hussein invaded Iran, hoping to exploit its post-revolutionary instability. The brutal conflict killed hundreds of thousands in one of the century's deadliest conflicts and forced Khomeini's government to consolidate power.

The last Shah of Iran came to power in 1941 and pursued rapid Westernization through his controversial reforms. His authoritarian rule, backed by the US, and his feared secret police, SAVAK, fueled mass resentment that ultimately drove him from power in 1979.

Just weeks after Khomeini's return, Iran held a national referendum to replace the monarchy with an Islamic Republic, and over 98% voted in favor (though the vote was criticized). The vote formalized the revolution's outcome, laying the foundation for a theocratic government that remains in place today.

Iran's democratically elected prime minister, Mosaddegh, nationalized the country's oil industry in 1951, challenging British and American control of Iran's resources. The CIA and British intelligence orchestrated a coup that ousted him and reinstated the Shah, fueling decades of Iranian distrust of the West.

A 2024 report classified Iran's mass executions of political prisoners in the 1980s as genocide and crimes against humanity, finding that thousands were arbitrarily killed under Khomeini's orders by "death committees" targeting perceived religious and political enemies.

From a defamatory newspaper editorial that sparked protests in January 1978 to Khomeini's return from exile and the Shah's flight from Iran in 1979, this timeline traces the rapidly escalating chain of events—protests, crackdowns, and political collapses—that toppled one of the Middle East's most powerful monarchies.

Despite thousands of unarmed protesters killed by the Shah's forces, the revolution relied overwhelmingly on nonviolent tactics, including strikes, demonstrations, and civil disobedience, with up to 9 million Iranians peacefully taking to the streets, making it one of history's largest protest movements by population percentage.

Greeted by millions of Iranians flooding the streets of Tehran, Khomeini's return was a defining moment of the revolution. Within days, he appointed a rival prime minister, effectively dismantling the last remnants of the Shah's government and consolidating clerical rule over the new Islamic Republic.

Exiled in 1964 for opposing a law that granted diplomatic immunity to US military personnel in Iran, Khomeini built a large following by smuggling recorded sermons into Iran on cassette tapes. He aimed to replace the monarchy with an Islamic republic governed by religious law.

Before nationalization, British companies controlled most of Iran's oil wealth, with little revenue returned to Iranians. Mosaddegh's decision made him a national hero at home but triggered a Western-led embargo and ultimately contributed to the coup that removed him from power.

At the request of Reza Shah, the international community began using "Iran"—the name Iranians had always called their country—replacing the Western term "Persia." The change reflected a broader push for national identity and modernization under the Pahlavi dynasty.

A popular revolution forced the ruling Qajar Shah—a dynasty that had governed Iran since the late 18th century—to sign a constitution and establish a parliament, marking Iran's first major step toward democratic governance and limiting the monarchy's absolute power.

As of 2023, nearly 20% of US electricity comes from nuclear power, but most reactors were built from 1971 to 1990. Expansion slowed due to safety concerns, high costs, and competition from natural gas.

Burning oil depots and bombed buildings are endangering the health of millions of people during the 2026 attacks. Heavy metals from munitions and other damaged materials are going airborne, but the exact health implications depends on dose, wind currents, and other factors including preexisting health conditions.

After learning that large atomic nuclei release energy upon being split apart, scientists quickly researched how to control the reaction to make electricity. Fusion—combining small atomic nuclei—generates massive energy in stars and hydrogen bombs.

A declassified 1976 US Embassy telegram acknowledged that the Shah held 3,400-3,500 political prisoners, documented torture allegations against the SAVAK secret police, and confirmed press censorship, even as American diplomats sought to minimize human rights concerns for Congress.

Oil passing through the Strait of Hormuz makes up only about 7% of US crude imports. However, crude oil prices account for 51% of the cost of a gallon of gas in the US. US refiners pay the Brent crude futures price, even for domestic drilling.

In 2023, these reactors—located in 53 plants across 28 states—prevented 437 million tons of carbon dioxide emissions. A single fingertip-sized uranium pellet generates as much electricity as a ton of coal, enough for one household's annual electricity.

Spoken by the majority of Iran's 90 million people, Persian is one of the world's oldest continuously spoken languages, with a literary tradition stretching back over a thousand years. It is also widely spoken in Afghanistan and Tajikistan.

All nuclear waste would have been stored at Nevada's Yucca Mountain, but the Obama administration indefinitely stalled the project after intense community backlash. Spent fuel is now stored at more than 80 locations in 36 states, raising safety concerns.

Across eight years (1980-88), Iran and Iraq each lost about $500 B in GDP, infrastructure destruction, military expenses, disrupted oil exports, and mounting debt—totaling over $1 T in economic damage.

In 1949, the USSR successfully tested its first atomic bomb—ending the US monopoly on nuclear weapons and sparking an arms race that would define the Cold War.

In the 1950s, the US considered detonating a hydrogen bomb on the moon as part of a Cold War show of force. Known as Project A119, the classified plan aimed to create a visible explosion from Earth to signal American dominance in the space race.

In the 1950s, the US considered detonating a hydrogen bomb on the moon as part of a Cold War show of force. Known as Project A119, the classified plan aimed to create a visible explosion from Earth to signal American dominance in the Space Race.

Spent nuclear fuel remains hot and highly radioactive for long periods, requiring submersion in cooling pools before being stored in dry casks and deep underground repositories. The potential recycling of nuclear waste is impeded by security concerns and dangerous reprocessing methods, particularly when obtaining fresh uranium is often easier.

Development and investment into geothermal energy took off in the 1960s. However, by the 1980s, companies repeatedly failed to find reservoirs of hot water when exploring new locations, and investors lost interest in the expensive drilling required. By the 2020s, technological advancements had finally helped mitigate exploration risk and expand viable drilling locations.

During the Cold War, the United States and the USSR were forced to prepare for a nuclear strike at a moment's notice, leading to a new innovation: the so-called "football" (known as the chemodanchik in Russia), a bag containing nuclear strike plans, authentication codes, and likely a communication device, which attended the country's leader wherever they went. This easy-to-read piece breaks down the history and lore around the high-stakes quirk in nuclear governance.

Due to energy shortages in Ukraine, Chernobyl's other undamaged reactors continued operating for years. Units 1 and 2 operated until 1996 and 1991, respectively, while Reactor 3 remained online until December 15, 2000, when Ukraine finally shut down the plant.

Creating the first atomic bombs demanded breakthroughs in physics, engineering, and logistics—uniting elite scientists with tens of thousands of workers across the US. This in-depth history explains how the Manhattan Project overcame those challenges.

During the 1980s, South Africa secretly built six uranium "gun‑type" nuclear bombs. In the 1990s, the government dismantled all its weapons and joined the NPT in 1991—the only country to fully reverse its nuclear program.