World War III

World War III, also called the Third World War, is an idea about a possible huge fight in the future after World War I and World War II. Many people think this kind of war would involve the world's biggest countries and might use nuclear weapons or other very powerful bombs. This would make it much worse than any war before.

At first, people thought World War III might happen during the Cold War between the United States and the Soviet Union. Even though both countries had nuclear weapons and there were many scary moments, like the Cuban Missile Crisis, they never fought each other directly. Instead, they had smaller wars in other places, like the Korean War and the Vietnam War.

Since the Cold War ended, people have worried about new dangers, like terrorism and attacks using computers. Today, some people are worried about fights between big countries like the United States, China, and Russia, and events like the war in Ukraine and tensions over Taiwan, as possible starts for a big future war.

Etymology

Time magazine was one of the first to use the term "World War III". It first appeared in an issue from November 1941, before the Japanese attack on Pearl Harbor in December 1941. The article talked about a belief that there might be a pause in fighting before Nazi leader Hermann Rauschning thought Hitler might try to invade Great Britain.

Later, in 1943, Time used the same title "World War III?" again when talking about US Vice President Henry A. Wallace. He mentioned that in 1943 or 1944, there might be a decision about whether a war could start between the United States and the Soviet Union. Time kept using the term "World War III" in many of its stories for years after that.

Military plans

Military experts have used special games, called war games, to practice for different kinds of wars and decide the best plans. They did this for both World War I and World War II.

Operation Unthinkable

Main article: Operation Unthinkable

In 1945, leaders from the United Kingdom created a plan called Operation Unthinkable. They worried that after World War II, the big Soviet army in Central and Eastern Europe might become a threat. The plan was to make sure the United States and Britain could control Russia. But other British leaders thought the plan would not work well in a real fight.

Operation Dropshot

Main article: Operation Dropshot

In 1949, the United States made a plan called Operation Dropshot for what might happen if they had to fight the Soviet Union. This plan included using nuclear weapons, but they were not expected to decide the war by themselves.

At that time, the US did not have many nuclear weapons, and they were kept mostly in the United States. The plan said they would drop 300 nuclear bombs and many other bombs on many places to damage the Soviet Union's ability to make things. Between 75 and 100 of the nuclear bombs would be used to destroy Soviet airplanes on the ground.

British-Irish cooperation

Ireland began to make plans in the late 1940s for what to do if there was a nuclear war. The United Kingdom and Ireland agreed to work together if such a war happened. They would share weather information, help with navigation, and plan for broadcasting after a nuclear attack. They also looked at the coasts of both countries to help the United States find places to land if needed. By 1953, they agreed to share weather information and help people from Britain move to Ireland if needed. This plan ended in 1966.

Seven Days to the River Rhine

Main article: Seven Days to the River Rhine

In 1979, countries in a group called the Warsaw Pact made a secret plan called Seven Days to the River Rhine. They started by assuming that a group of countries called NATO might use nuclear weapons first. In response, the Warsaw Pact would attack West Germany, Belgium, the Netherlands and Denmark. Their goal was to reach the River Rhine in seven days. Some plans went even further, aiming for the French border by the ninth day. This plan expected many people to be hurt by radiation and many soldiers to become sick. It also thought NATO might use nuclear weapons to stop the Warsaw Pact forces.

NATO nuclear sharing

Main article: Nuclear sharing

Some countries in NATO, a group of friendly countries, have plans for using nuclear weapons in a big war. These countries do not have their own nuclear weapons, but they can use ones supplied by the United States. As of 2009, Belgium, Germany, Italy, the Netherlands and Turkey kept US nuclear weapons. In times of peace, these weapons are guarded by US airmen, and only the United States can use them. In a war, they would be placed on airplanes from these countries. As of 2005, about 180 of the 480 US nuclear weapons in Europe were kept in special, strong buildings and ready to be used by airplanes like the F-16 Fighting Falcons and Panavia Tornados.

Historical conflicts and incidents

Main article: Nuclear warfare

See also: List of nuclear close calls

When the Cold War began in the 1950s, some worried that a big war between the United States and the Soviet Union might happen. During the Cold War (1947–1991), several events almost led to a bigger conflict.

Cold War

Main article: Cold War

After World War II, relations between the Soviet Union and the United States were tense. Many people were afraid this tension could turn into a larger war. In 1950, a poll showed that over half of Americans thought a big war had already started.

Some say the Cold War itself could be called a big world war, but most historians say a true World War III needs many countries fighting together. The Cold War didn’t turn into a real fight because the two sides were scared of using nuclear weapons.

Korean War: 25 June 1950 – 27 July 1953

Main articles: Korean conflict and Korean War

The Korean War was a fight over the Korean Peninsula. North Korea, with help from China and the Soviet Union, fought against South Korea, with help from the United States and the United Nations Command. Some thought this could grow into a bigger war involving more countries.

Cuban Missile Crisis: 15–29 October 1962

Main articles: Cuban Missile Crisis and Soviet submarine B-59

The Cuban Missile Crisis was a scary time when the Soviet Union put nuclear missiles in Cuba. This almost led to a nuclear war between the United States and the Soviet Union. On one day, three big things happened:

• A Soviet submarine almost launched a nuclear weapon when American ships tried to stop it.
• A United States spy plane was shot down over Cuba.
• Another spy plane almost entered Soviet airspace, causing worry.

Even though things were very tense, leaders managed to avoid a war. After this, leaders set up better ways to talk to each other to prevent future crises.

Yom Kippur War superpower tensions: 6–25 October 1973

Main article: Yom Kippur War

The Yom Kippur War started when Arab countries attacked areas controlled by Israel. The United States and the Soviet Union, who supported different sides, came close to fighting each other. Luckily, a ceasefire stopped the conflict.

NORAD computer error: 9 November 1979

The United States prepared for a possible attack after a mistake in their warning systems said the Soviet Union was launching missiles. They later found out it was a test and not a real attack.

Soviet radar malfunction: 26 September 1983

Main article: 1983 Soviet nuclear false alarm incident

A mistake in the Soviet Union’s warning system made it look like the United States was launching missiles. An officer decided it was a mistake, and a war was avoided.

Able Archer 83 escalations: 2–11 November 1983

Main article: Able Archer 83

A military exercise by the United States and its allies worried some leaders in the Soviet Union that it was a real attack. The Soviet Union prepared to respond, but the exercise ended without any real fighting.

Norwegian rocket incident: 25 January 1995

Main article: Norwegian rocket incident

Russia thought a science rocket from Norway was a missile attack. They were ready to respond, but soon learned it was not a threat.

Incident at Pristina airport: 12 June 1999

Main articles: Incident at Pristina airport and Mike Jackson (British Army officer)

After a war in Kosovo, Russian peacekeepers took control of an airport before NATO troops arrived. A NATO general wanted to use force, but a British general refused, saying he would not start a big war over it.

War on terror

Main articles: War on terror and List of modern conflicts in the Middle East

"World War IV" redirects here. For the play-by-mail game, see World War IV (play-by-mail game). For the 2003 film, see The Fourth World War.

Some people have called the fight against terrorism after the September 11 attacks a world war, but historians usually don’t agree because it wasn’t fought by many countries in the same way as the first two world wars.

War on the Islamic State

Main articles: Islamic State and War against the Islamic State

In 2015, some leaders said the fight against a group called the Islamic State was like a world war because the group wanted to control many countries. Others said this was an overstatement.

Shootdown of Sukhoi bomber: 24 November 2015

Main article: 2015 Russian Sukhoi Su-24 shootdown

In 2015, Turkey shot down a Russian airplane near their border. This happened during a conflict in Syria. Some people worried this could lead to a bigger war, but it did not.

Current potential flashpoints

China–Taiwan tensions

Main articles: Cross-strait relations and Fourth Taiwan Strait Crisis

After a long-ago war between groups in China, two different governments formed. One is based in China, and the other is based in Taiwan. The government in China says Taiwan is part of its country, even though Taiwan runs itself. Recently, China has made big threats and moved its military close to Taiwan, saying it might use force to bring Taiwan under its control. This has made many people worry about possible fighting.

Russo-Ukrainian War (2022–present)

Main articles: Russo-Ukrainian war (2022–present) and Nuclear risk during the Russo-Ukrainian war (2022–present)

In February 2022, Russia started a big war in Ukraine. This was the largest fighting in Europe since World War II. Many experts worry this could grow into a bigger global war. NATO countries have helped Ukraine defend itself, but there have been moments when the fighting almost involved NATO directly. Some Russian leaders have made strong warnings, but so far, no nuclear weapons have been used.

2026 Iran war

Main article: 2026 Iran war

See also: Middle Eastern crisis (2023–present)

In February 2026, the United States and Israel attacked Iran, causing many leaders there to be killed. Iran responded with attacks on Israel and US forces, leading to a big fight in the Middle East. Some people believe this conflict could become a third world war because it involved many countries and could affect the whole world.

Hypothetical scenarios

After World War II, when nuclear weapons were created, scientist Albert Einstein said that if there ever was a World War III, it might be so bad that it would set humanity back to a very old way of living. He wasn’t sure what kind of weapons might be used in such a war.

Some people have thought about different ways a big future war might start. They mention possible tensions between countries like Russia and Ukraine, China and its neighbors, or India and Pakistan. Even smaller conflicts could grow into larger wars if other big countries get involved.

There have also been worries about what might happen if nuclear weapons were used. Some studies suggest that a big nuclear war could cause huge problems for food and climate, affecting many people around the world.

New technologies, like artificial intelligence and cyberattacks, might also create new risks. Countries are paying more attention to protecting their computer systems and information from attacks by other nations. The fighting in Ukraine has included attacks on computer systems, showing how important cyber safety has become.

Multiple wars as a third world war

Some leaders and experts have talked about the idea of a third world war happening because of many big fights happening around the world at the same time. Pope Francis said the world is at war because it has lost peace, and might even call it a third war happening bit by bit. His successor, Pope Leo XIV, agreed with this during a visit to Turkey in 2025. Fiona Hill also thinks that big conflicts, like in Ukraine and the Middle East, could be part of a third world war. A poll by Politico showed that many people in America, Canada, France, and Britain think it’s likely a big war could start in the next five years. They point to Russia’s actions in Ukraine and US military actions in Iran, Syria, Venezuela, and Africa as reasons why this might happen.

In fiction

People often imagine a big future war called World War III in stories and movies. This idea appears a lot in science fiction and other types of popular culture. It’s a way for writers and creators to explore what might happen if countries around the world had a huge conflict.