Open city

In war, an open city is a place that has said it will not try to defend itself when an enemy is about to arrive. This is done to keep the city from being destroyed. When a city says it is open, the enemy is supposed to take over peacefully instead of fighting and causing damage, as rules under international law say.

The idea of an open city started in World War I. Cities would remove their soldiers and weapons to try to stay safe from attacks. Protocol I of the Geneva Conventions says that attacking forces cannot attack places that are not defended. This helps protect ordinary people and important buildings.

However, not all attacking forces always follow this rule. Sometimes, the people declaring a city open are trying to use it as a trick for their own purposes. In other cases, the city may be open because the people there are about to give up, or they may still want to fight but just want to save that one city. Even in open cities, there can still be groups trying to fight back, which makes it hard for the occupying forces to behave calmly and carefully.

Examples

19th century

During the 1814 Battle of Paris near the end of the Napoleonic Wars, Paris was treated like an open city. After tough fighting outside the city on March 30, 1814, the defenders decided to leave Paris to avoid destroying it. The next day, soldiers from Russia, Austria, Prussia, and Württemberg entered the city.

World War II

Many cities were declared open during World War II:

• Kraków was left without strong defenses after a Polish army unit moved out of the city. The mayor declared it an open city on September 5, 1939, and German soldiers entered the next day.
• Brussels was declared an open city by Belgium on May 17, 1940, and was occupied by German forces.
• Paris was declared an open city by France on June 11, 1940, as the government moved to Bordeaux.
• Belgrade was declared open on April 5, 1941, but German forces bombed the city anyway.
• Manila was declared open by American General Douglas MacArthur on December 26, 1941, but Japanese forces still bombed it.
• Batavia (now Jakarta) was declared open on March 5, 1942 after Dutch soldiers left, and Japanese forces entered the next day.
• Rome was declared open on August 14, 1943. Allied forces entered Rome in June 1944, and German forces also declared Florence and Chieti open cities in March 1944.
• Athens was declared an open city by German forces on October 11, 1944.
• Hamburg was declared open on May 3, 1945, and was occupied by British soldiers.

Post-World War II Japan

In 1977, a group in Japan wanted cities to declare themselves "defenseless" under international law in case of war. This idea was rejected by most political parties and the government. However, the Social Democratic Party supported it. Some areas of Tokyo and Kagoshima City considered making this declaration.

Afghanistan

When President Ashraf Ghani left Afghanistan during the 2021 Taliban offensive, Kabul the capital, was effectively declared an open city. This allowed the Taliban to take control without a fight, but it also led to the quick end of the government.