One of the purposes for which the First Hague Peace Conference of 1899 was convened was "the revision of the declaration concerning the laws and customs of war elaborated in 1874 by the Conference of Brussels, and not yet ratified" (Russian circular note of 30 December 1898). The Conference of 1899 succeeded in adopting a Convention on land warfare to which Regulations are annexed. The Convention and the Regulations were revised at the Second International Peace Conference in 1907. The two versions of the Convention and the Regulations differ only slightly from each other.
Seventeen of the States which ratified the 1899 Convention did not ratify the 1907 version (Argentina, Bulgaria, Chile, Colombia, Ecuador, Greece, Italy, Korea, Montenegro, Paraguay, Persia, Peru, Serbia, Spain, Turkey, Uruguay, Venezuela). These States or their successor States remain formally bound by the 1899 Convention in their relations with the other parties thereto. As between the parties to the 1907 Convention, this Convention has replaced the 1899 Convention (see Article 4 of the 1907 Convention).
The provisions of the two Conventions on land warfare, like most of the substantive provisions of the Hague Conventions of 1899 and 1907, are considered as embodying rules of customary international law. As such they are also binding on States which are not formally parties to them.
In 1946 the Nüremberg International Military Tribunal stated with regard to the Hague Convention on land warfare of 1907: "The rules of land warfare expressed in the Convention undoubtedly represented an advance over existing International Law at the time of their adoption ... but by 1939 these rules ... were recognized by all civilized nations and were regarded as being declaratory of the laws and customs of war" (reprinted in AJIL, Vol. 41, 1947, pp. 248-249). The International Military Tribunal for the Far East expressed, in 1948, an identical view.
The rules embodied in the Regulations were partly reaffirmed and developed by the two Protocols Additional to the Geneva Conventions of 1949 adopted in 1977.
D.Schindler and J.Toman, The Laws of Armed Conflicts, Martinus Nijhoff Publisher, 1988, pp.69-93.