Indiscriminate attack
[13] Under current international humanitarian law, however, attacks against a legitimate military objective that lead to collateral damages are subject to the principle of proportionality:[11][14][15] losses to the civilian population and damage to civilian objects must not be "excessive in relation to the concrete and direct military advantage anticipated" from the attack, as stated in Article 51 Protocol I.
[16] The prohibition of indiscriminate attacks is set forth in Article 51(4) and (5) of Additional Protocol I[note 2] and is generally considered a norm of customary international humanitarian law.
Strategic bombing by German forces using airships (such as the Zeppelin raids over England and during the siege of Antwerp) and long-range artillery (the "Big Bertha" cannon) raised the issue of how to contain indiscriminate military attacks.
At the 1932 World Disarmament Conference, the British government argued that limitations to aerial warfare should not apply to colonies: as Prime Minister David Lloyd George declared, "we insisted on reserving the right to bomb niggers".
[27] As British Prime Minister Neville Chamberlain stated to the House of Commons of the United Kingdom in June 1938: there was "no international code of law with respect to aerial warfare which is the subject of general agreement.
"[28] At the onset of the war, U.S. President Franklin D. Roosevelt attempted to mitigate this situation by launching an Appeal to the Belligerents to Refrain from the Bombing of Open Towns.
[29] The appeal was accepted by the German, French and British governments[24][30] and proved to be quite effective in practice, as during World War II it remained an option to declare a city "open", abandon all defensive efforts and avoid bombing, as happened in Paris, Brussels, Rome, Athens and elsewhere.
[32] "Reprisals" could lawfully follow any belligerent's bombardment of civilians, which was the legal ramification of the norm of reciprocity",[29] and with the indiscriminate attacks by German forces against Polish targets during the invasion of Poland that began in September 1939 the norm of reciprocity "was the only guarantor of a fighting chance at survival in the face of an enemy who disregarded important humanitarian principles".
Their bombing campaigns had arguably been paralleled or surpassed by those carried out by the Allies, and in the Nuremberg and Tokyo indictments no attempt was made to frame indiscriminate attacks as war crimes.
[40][41][42] During the negotiations of the 1949 Geneva Conventions, protection of civilians was a controversial subject, and the British representatives opposed any restriction to the freedom to carry out bombing – at the time, both France and the United Kingdom were engaged in "aerial policing" as part of counterinsurgency efforts in their colonial empires.
However, Article 13 of Protocol II does state that civilians are entitled to protection "against the dangers arising from military operations", which is construed as indirectly banning indiscriminate attacks.
[51] As of November 2023, the Protocol had been ratified by 169 countries, with the United States, India, Pakistan, Turkey, Iran, Iraq, Syria, and Israel being notable exceptions.
[54] At the time of the Gulf War, many legal scholars doubted that Protocol I codified customary international humanitarian law and was therefore binding upon the United States, which had not signed the convention.
[55] Human Rights Watch published a report arguing that "many of the Protocol’s provisions", including the prohibition of disproportionate and other indiscriminate attacks, "reaffirm, clarify or otherwise codify pre-existing customary law restraints on methods and means of combat and, thus, are binding on all nations regardless of ratification".
[59] Human rights groups have claimed that the Syrian Armed Forces are responsible for a systematic campaign of indiscriminate attacks in cities all across the country.
