Open City

In war, in the event of the imminent capture of a city, the government/military structure of the nation that controls the city will sometimes declare it an open city, thus announcing that they have abandoned all defensive efforts.

The attacking armies of the opposing military will then be expected not to bomb or otherwise attack the city, but simply to march in. The concept aims at protecting the historic landmarks and civilians who dwell in the city from an unnecessary battle.

Some examples of declarations of an open city include:

• Brussels in 1940, World War II
• Paris in 1940, from which the French Government fled after it became apparent that they could not defend it
• Belgrade in April 1941, World War II
• Manila in 1942, which the American military abandoned because they could not defend it against the surprise Japanese invasion.
• Athens on 11 October 1944 was declared an open city by the Germans
• Rome on 14 August 1943, which the defending Italian forces declared unilaterally to be an "open city" following the cessation of Allied bombing and this applied when under attack by the Germans; subsequently Allied forces entered Rome in June 1944 and retreating German forces also declared Florence and Chieti "open cities".

Attacking forces do not always respect the declaration of an "open city." Defensive forces will use it as a political tactic as well.