Air and naval warfare and international humanitarian law
All armed conflicts are covered by the basic rules and principles of IHL, wherever the theatre of operations might be, land, sea or air. Nevertheless, some treaty and customary law specifically refers to certain aspects of naval and aerial warfare.
Until World War I, war at sea had been governed primarily by the Hague treaties and customary law. However, the means and methods of warfare during that conflict, in particular the use of submarines and attacks on neutral shipping, raised questions about how IHL was being applied. In World War II arbitrary attacks on hospital ships and Red Cross vessels carrying relief supplies again raised the issue of whether the balance between military and humanitarian needs in customary naval law was being respected.
Questions of civilian safety, the use of blockades and exclusion zones at sea continued to be raised in the naval wars in the Falkland/Malvinas Islands, in the Iran–Iraq War and in the Gulf War. However, no new major treaty governing naval war was considered by the international community. Instead, non-binding guidelines, namely the San Remo Manual of 1994, were drawn up by government officials, the ICRC, a number of National Red Cross and Red Crescent Societies and other experts.
The manual essentially reaffirmed and updated the interpretation of IHL as applied to war at sea.
It clarifies how the principle of distinction is applied at sea, based on 1977’s Protocol I additional to the Geneva Conventions, including by defining what a military objective is. Warships are military objectives, as are auxiliary vessels and merchant ships that directly help the enemy’s military action.
The manual provides a list of activities that would cause a non-military vessel to become a legitimate military target. The list includes such examples as laying mines, carrying troops, gathering intelligence, sailing under military convoy, resisting stop and search, and carrying a significant armament.
Equally the manual lists ships that may not be attacked, such as hospital ships, coastal rescue craft, vessels carrying prisoners of war, passenger vessels carrying only civilians, coastal fishing craft and lifeboats.
The manual limits itself primarily to IHL's application at sea during armed conflict. More general legal issues of public international law are covered by the 1982 Convention on the Law of the Sea. The manual does, however, reaffirm that IHL cannot be set aside in circumstances covered by that law, such as exclusion zones.
Compared with naval warfare, aerial warfare is relatively modern. Balloons existed before aircraft, and their use in war was regulated in 1899, but aircraft as such were not in use in warfare until the early years of the 20th century.
Aircraft were extensively used in World War II. The Battle of Britain was an air battle; the war in the Pacific depended on close integration of naval and air power. The bombing campaigns of World War II claimed many civilian lives and contributed to the demands for regulation that led to the Fourth Geneva Convention and the subsequent Additional Protocols.
Although states have yet to adopt a specific regulation of modern air warfare, the general principles and rules of IHL clearly apply. Aerial bombardment, for example, must be carried out according to the principles of IHL, distinguishing between military targets and civilians and being proportionate in nature.
As well, international conventions banning the use of various weapons, for example chemical and bacteriological weapons, pertain directly to aerial warfare.
During naval and air operations, parties have an obligation not to cause unnecessary environmental damage to land or sea or to gratuitously deprive civilians of their means of survival. IHL also protects cultural objects from aerial or naval attack.
