International humanitarian law prohibits or restricts the use of conventional weapons in order to moderate the effects of wars on the civilian population.

Common law gives rise to regulations such as:

• the prohibition of weapons that may have indiscriminate effects
• the prohibition of weapons that cause unnecessary suffering.

The Convention of 10.10.1980 on Prohibitions or Restrictions on the Use of Certain Conventional Weapons, widely known as the Inhumane Weapons Convention, is crucially important. In addition to the chapeau convention, the content of which is of a general nature, three annexed protocols prohibit or restrict the use of certain categories of weapon:

• protocol I on non-detectable fragments
• protocol II on mines, booby traps and other devices
• protocol III on incendiary weapons.

The Convention, which was designed to be flexible, has been amended in the light of the rapid development of weapons technology and military science since 1980. Its scope has been extended by the amendment of protocol II on mines, booby traps and other devices and the addition of two new protocols:

• protocol IV on blinding laser weapons (1995)
• protocol V on the explosive remnants of war (2003).

In addition to the regulations on behaviour in armed conflict, the Convention also prescribes measures covering the periods preceding the commencement of hostilities and following their cessation. The scope of the Convention was extended to cover domestic conflicts in 2001.

Switzerland has ratified the chapeau convention and its five protocols. It is actively involved in the work of government experts on regulations for other types of weapon that the Convention does not yet cover.