United States of America
Practice Relating to Rule 117. Accounting for Missing Persons
Section B. Provision of information on missing persons
The US Field Manual (1956) reproduces Article 122 of the 1949 Geneva Convention III and Articles 136 and 137 of the 1949 Geneva Convention IV.
The US Naval Handbook (2007) states: “The  Geneva Conventions recognize the special status of the ICRC and have assigned specific tasks for it to perform, including … searching for information concerning missing persons.”
The US National Defense Authorization Act for Fiscal Year 2010 (2009) provides for the following authorisation:
Sec. 541. Additional Requirements for Accounting for Members of the Armed Forces and Department of Defense Civilian Employees Listed as Missing in Conflicts Occurring Before Enactment of New System for Accounting for Missing Persons
(a) IMPOSITION OF ADDITIONAL REQUIREMENTS.—Section 1509 of title 10, United States Code, is amended to read as follows:
“§ 1509. Program to resolve pre-enactment missing person cases
“(a) PROGRAM REQUIRED; COVERED CONFLICTS.—The Secretary of Defense shall implement a comprehensive, coordinated, integrated, and fully resourced program to account for persons described in subparagraph (A) or (B) of section 1513(1) of this title who are unaccounted for from the following conflicts:
“(1) World War II during the period beginning on December 7, 1941, and ending on December 31, 1946, including members of the armed forces who were lost during flight operations in the Pacific theater of operations covered by section 576 of the National Defense Authorization Act for Fiscal Year 2000 (Public Law 106–65; 10 U.S.C. 1501 note).
“(2) The Cold War during the period beginning on September 2, 1945, and ending on August 21, 1991.
“(3) The Korean War during the period beginning on June 27, 1950, and ending on January 31, 1955.
“(4) The Indochina War era during the period beginning on July 8, 1959, and ending on May 15, 1975.
“(5) The Persian Gulf War during the period beginning on August 2, 1990, and ending on February 28, 1991.
“(6) Such other conflicts in which members of the armed forces served as the Secretary of Defense may designate.
“(d) ESTABLISHMENT OF PERSONNEL FILES.—(1) The Secretary of Defense shall ensure that a personnel file is established and maintained for each person covered by subsection (a) if the Secretary—
“(A) possesses any information relevant to the status of the person; or
“(B) receives any new information regarding the missing person as provided in subsection (e).
“(2) The Secretary of Defense shall ensure that each file established under this subsection contains all relevant information pertaining to a person covered by subsection (a) and is readily accessible to all elements of the department, the combatant commands, and the armed forces involved in the effort to account for the person.
According to the Report on US Practice, it is the opinio juris
of the United States that the parties to all armed conflicts should take such action as may be within their power to provide information about missing persons.