Related Rule
South Africa
Practice Relating to Rule 139. Respect for International Humanitarian Law
South Africa’s Revised Civic Education Manual (2004) states:
The respect for and unconditional application of the LOAC by all members of the SANDF [South African National Defence Force] is of paramount importance to ensure the retention and maintenance of its moral and ethical standards. 
South Africa, Revised Civic Education Manual, South African National Defence Force, 2004, Chapter 4, § 94.
In 2004, in the Basson case before the Constitutional Court of South Africa, Justice Sachs stated in his concurring opinion:
Section 232 of the Constitution states:
“Customary international law is law in the Republic unless it is inconsistent with the Constitution or an Act of Parliament.”
The rules of humanitarian law constitute an important ingredient of customary international law. As the International Court of Justice [ICJ] has stated, they are fundamental to the respect of the human person and “elementary considerations of humanity”. The rules of humanitarian law in armed conflicts are to be observed by all states whether or not they have ratified the Conventions that contain them because they constitute intransgressible principles of international customary law. The ICJ has also stressed that the obligation on all governments to respect the Geneva Conventions in all circumstances does not derive from the Conventions themselves, but from the general principles of humanitarian law to which the Conventions merely give specific expression. 
South Africa, Constitutional Court, Basson case¸ Judgment, 10 March 2004, § 122.
In its judgment in the Basson II case in 2005, the Constitutional Court of South Africa stated:
South Africa was a party to the Geneva Conventions. Yet as the ICJ [International Court of Justice] pointed out in Nicaragua v United States of America, even if South Africa had not been a party, it would have been obliged in the 1980s to respect the [1949 Geneva] Conventions in all circumstances “since such an obligation does not derive only from the Conventions themselves, but from the general principles of humanitarian law to which the Conventions merely give specific expression”. 
South Africa, Constitutional Court, Basson II case¸ Judgment, 9 September 2005, § 177.
In 1999, during a debate on the UN Decade of International Law in the Sixth Committee of the UN General Assembly, South Africa stated:
The rules of international humanitarian law should also be subject to constant revision, in the sense not of making new laws but of ensuring compliance with existing ones. States should work to instil a culture of compliance. 
South Africa, Statement before the Sixth Committee of the UN General Assembly, UN Doc. A/C.6/54/SR.10, 19 October 1999, § 76.