In war, an open city is a settlement which has announced it has abandoned all defensive efforts, generally in the event of the imminent capture of the city to avoid destruction. Once a city has declared itself open the opposing military will be expected under international law to peacefully occupy the city rather than destroy it. According to the Protocol I of the Geneva Conventions, it is forbidden for the attacking party to "attack, by any means whatsoever, non-defended localities". The intent is to protect the city's civilians and cultural landmarks from a battle which may be futile. Attacking forces do not always respect the declaration of an "open city". Defensive forces will occasionally use the designation as a political tactic as well. In some cases, the declaration of a city to be "open" is made by a side on the verge of defeat and surrender; in other cases, those making such a declaration are willing and able to fight on but prefer that the specific city be spared. Often resistance movements will be active in open cities, straining the temperate conduct of the occupying forces. Examples Numerous cities were declared open cities during World War II, most notably Paris: Kraków was left undefended (except for some small local units) after the Polish 6th Infantry Division marched by the city to the nearby Niepołomice Forest to set new defensive lines during the German invasion of Poland. This led the Mayor of Kraków to declare it an open city on 5 September 1939. The German Army entered the city the next day. Brussels was declared an open city by the Belgian Government in 1940 during the Battle of Belgium. It was later occupied by the Germans. Paris was declared an open city by the French Government in June 1940 during the Battle of France. Belgrade was declared open in April 1941 by the Kingdom of Yugoslavia, just before the Invasion of Yugoslavia. The German Wehrmacht did not respect the open city status and heavily bombed the city. Manila was declared an open city on 26 December 1941 by US general Douglas MacArthur during the Japanese invasion of the Philippines. The Imperial Japanese Army ignored the declaration and bombed the city. However, the United States Armed Forces were still using the city for logistical purposes at the time of the bombings. Batavia was declared an open city on 5 March 1942 after