The alliance operates under a "flexible response" doctrine—that is, proportionality

Members decide to what extent they respond to an attack on an ally

The NATO constitution is intentionally vague about what exactly is required from its members. Explore the historical debates and learn more about common misconceptions about NATO’s common defense clause.

How NATO works

NATO now includes 32 member nations—but how does the alliance actually function? This explainer breaks down its structure, decision-making process, and funding model. From its founding in 1949 to its collective response after 9/11, here’s how NATO operates on a global scale.

NATO's Article 5 has been invoked once—after 9/11

The article was invoked the day after the attacks and launched a series of NATO campaigns to fight global terrorism. This page includes excerpts from a speech by then-NATO Secretary General Jens Stoltenberg about the attacks and the organization’s response.

NATO was formed in 1949 to deter Soviet expansion and integrate Europe

Europe was in shambles after World War II, which saw 36 million Europeans killed, and the Soviets were looking to increase their influence. Beyond deterring the Soviets, the alliance sought to restore Europe and prevent nationalist militarism akin to the German Nazis and Italian Fascists.

Decisions at NATO are by consensus and must be unanimous

There are two strategic commands in NATO: one in Europe (Supreme Allied Headquarters Command Europe) and another in Norfolk, Virginia (Allied Command Transformation). The alliance is headed by both a military officer and a civilian leader.

Questions about the US' commitment to its allies may have sparked a new nuclear age

Some US allies—from Warsaw to Seoul—are reevaluating their security amid doubts over American nuclear commitment, signaling the possibility they may want to acquire their own weapons.

NATO condemned Russia's 2022 invasion of Ukraine

While Ukraine is not a member, NATO responded forcefully to the Russian invasion of the country in 2022. This page from the NATO website offers answers to frequently asked questions about NATO’s response to the invasion, specifically on how NATO is aiding Ukraine.

The threat of nuclear annihilation reshaped global diplomacy

The first use of atomic weapons introduced the possibility of a war with no survivors. This article examines how nuclear fear shaped Cold War diplomacy and continues to influence international relations today.

Nuclear weapons release energy through rapid atomic reactions

Nuclear weapons work by unleashing energy from atomic fission—or fusion—reactions. In fission bombs, a critical mass triggers a runaway chain reaction in milliseconds. This video explains the basic science behind their immense explosive power.

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 Non‑Proliferation Treaty was designed to prevent new states from developing nuclear bombs

The Treaty on the Non‑Proliferation of Nuclear Weapons (created in 1968, effective 1970) binds non-nuclear states to forgo nuclear weapons and commits nuclear powers to share peaceful technology and pursue disarmament—forming the core of the global non-proliferation regime.

A 'nuclear football' briefcase always accompanies the president

The "nuclear football," carried by a military aide to the president at all times, contains communication equipment that allows the president to order a nuclear strike from anywhere in the world. The president carries "the biscuit," a plastic card containing the launch codes, which are changed daily.

The global nuclear arms regime has slowly eroded over the past few decades

Both Russia and the United States have withdrawn from key Cold War-era arms-control pacts. Russia's 2022 invasion of Ukraine marked a turning point, as it suspended its participation in inspections and data-sharing agreements.

The 1955 Warsaw Pact was the Soviet Union’s answer to NATO

The pact included Albania, Bulgaria, Czechoslovakia, East Germany, Hungary, Poland, Romania, and the USSR. The pact established collective security and a joint military command between the member countries.

China doubled its nuclear stockpile between 2020 and 2025, with plans for further expansion

China's arsenal grew from an estimated 300 warheads in 2020 to approximately 600 in 2025—making it the world's third-largest nuclear power. The US Department of Defense projects that China will surpass 1,000 warheads by 2030.

A list of reasons against dropping the bomb on Japan

One of the perennial moral debates, the dropping of nuclear bombs on Japanese cities prompted strong, polarizing reactions at the time. This article breaks down one side of the argument: that the bomb was designed for defense, using it was illegal and racist, and that there were alternatives.

Bill Nye believes a World War II-level mobilization is needed to end climate change

As part of his science advocacy efforts, Nye has argued that existing technologies, including electric vehicles and renewable energy, can already significantly reduce emissions. However, switching to these technologies requires a more expansive awareness of the problem and a greater sociopolitical willingness by policymakers and the general public.

North Korea, in nine infographics

In recent decades, North Korea has spent nearly a third of its annual Gross Domestic Product on military spending, although data is not always forthcoming. This spending has funded major nuclear and missile projects as a means to deter attacks from...

Newton's laws describe how objects resist acceleration and respond to forces

Newton’s first law defines inertia as the tendency of an object to maintain its velocity. His second law connects external force, inertia, and acceleration, while his third law states that forces come in pairs—every action has an equal and opposite reaction.

The National Guard serves both state governors and presidents

Roughly 430,000 trained military personnel act as a strategic reserve for the US military, deployed domestically during natural disasters or unrest as well as overseas. It consists of the Army National Guard and the Air National Guard, overseen at the federal level by the National Guard Bureau.

Defending Earth against asteroids

This three-minute video overview explains NASA's ambitious test to slightly alter the course of an asteroid by slamming a fast-moving space probe into its surface. Scientists hope to one day, if needed, use the technique to protect Earth from an asteroid impact.

Dario Amodei explains what led to his company being designated a supply chain risk

When pressed about the use of Claude in the capture of former Venezuelan President Nicolás Maduro, Anthropic's CEO acknowledged its contract with the Pentagon. However, he also emphasized that Claude is not to be used for mass surveillance or autonomous weapons, in part because the technology is not yet safe or reliable for such uses.

What is the Responsibility to Protect?

This website provides an in-depth overview of the Responsibility to Protect. An important global principle, R2P seeks to safeguard populations from genocide, war crimes, crimes against humanity and ethnic cleansing. The website’s ‘What is...

Why does the body have a stress response?

When encountering a stressful situation, the human body typically goes into what is known as "fight-or-flight" mode. Because it evolved as a survival mechanism, the biochemical response enables people and other mammals to react quickly to life-threatening situations. The carefully orchestrated yet near-instantaneous sequence of hormonal changes and physiological responses helps someone to fight the threat off or flee to safety.

Norway operates the largest SWF in the world—managing more than $2T in assets

The fund is considered the gold standard SWF because of its transparency around investments, politically independent governance, and strong ethical boundaries that serve as the backbone of the investment philosophy. For example, fund managers will not invest in coal, tobacco, or nuclear weapons, because these investments are considered harmful to humanity.

How fusion—which releases energy when two lighter atoms combine to form a heavier atom—differs from fission

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.

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

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

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

In 2025, four executives from large tech companies were given positions in the US Army Reserves—including Palantir Chief Technology Officer Shyam Sankar, which reinforced Palantir's ties with the US military and its role as a leading defense partner.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.

Power lines are dotted with large, brightly colored balls to improve the visibility of these thin wires to helicopters and small planes and help prevent potential crashes.

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

An investigation suggests a Scottish island became awash in forever chemicals via seafoam and seaspray—raising questions about what that means for the safety of other coastal areas.

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.

In 2026, Finland was named the world's happiest country for the ninth consecutive year based on its wealth, social safety network, and high life expectancy, among other factors.

Prince's sexually explicit 1984 track 'Darling Nikki' attracted the ire of the Parents Music Resource Center, an advocacy group that inspired the Parental Advisory sticker, even though the song ends with a Christian message.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

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.