Related Rule
United States of America
Practice Relating to Rule 121. Location of Internment and Detention Centres
The US Field Manual (1956) states: “The Detaining Power shall not set up places of internment in areas particularly exposed to the dangers of war.” 
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, § 290.
The manual also states: “Prisoners of war may be interned only in premises located on land and affording every guarantee of hygiene and healthfulness.” 
United States, Field Manual 27-10, The Law of Land Warfare, US Department of the Army, 18 July 1956, as modified by Change No. 1, 15 July 1976, § 98.
The US Air Force Pamphlet (1976) requires “internment only on land and not in unhealthy areas”. 
United States, Air Force Pamphlet 110-31, International Law – The Conduct of Armed Conflict and Air Operations, US Department of the Air Force, 1976, § 13-4.
The US Naval Handbook (2007) states: “All detainees shall … [b]e removed as soon as practicable from the point of capture and transported to detainee collection points, holding facilities, or other internment facilities operated by DOD [Department of Defense] Components.” 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, § 11.2.
The Handbook also states:
International treaty law expressly prohibits “internment” of prisoners of war other than in premises on land, but does not address temporary stay on board vessels. U.S. policy permits detention of prisoners-of-war, civilian internees, and detained persons on naval vessels as follows:
1. When picked up at sea, they may be temporarily held on board as operational needs dictate, pending a reasonable opportunity to transfer them to a shore facility or to another vessel for evacuation to a shore facility.
2. They may be temporarily held on board naval vessels while being transported between land facilities.
3. They may be temporarily held on board naval vessels if such detention would appreciably improve their safety or health prospects.
Detention on board vessels must be truly temporary, limited to the minimum period necessary to evacuate such persons from the combat zone or to avoid significant harm such persons would face if detained on land. Use of immobilized vessels for temporary detention of prisoners of war, civilian internees, or detained persons is not authorized without Secretary of Defense approval. 
United States, The Commander’s Handbook on the Law of Naval Operations, NWP 1-14M/MCWP 5-12.1/COMDTPUB P5800.7, issued by the Department of the Navy, Office of the Chief of Naval Operations and Headquarters, US Marine Corps, and Department of Homeland Security, US Coast Guard, July 2007, § 11.3.1.4.
The US Manual on Detainee Operations (2008) states: “Force Protection. To the maximum extent possible, places of detention will be protected from the hazards of the battlefield … As a general rule, detainees should derive the same benefit from force protection measures as do members of the detaining force.” 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, pp. III-6–III-7.
In a chapter on “Capture and Initial Detention and Screening”, the manual states:
Consistent with longstanding military practice, individuals captured or detained by U.S. forces must be evacuated expeditiously through transit points to reach an internment facility in a secure area.
When captured, detainees will normally be held at the detainee collection point (DCP) pending their immediate evacuation. The DCP will support the rapid transfer of control from capturing forces to U.S. MP custody and control … It should therefore be located close to the area of actual operations for quick evacuation of detainees, but should also be situated in a location intended to provide for the safety and security of the detainees and the security force. For example, the DCP could normally be located in a brigade support area of the brigade combat team, or an equivalent type unit. Detainees should be transported from the DCP to the detainee holding area (DHA) as soon as practicable. The DHA will normally be located in a secure location that provides safety and is easily accessible for receipt and evacuation of detainees …
… The DHA should be located in a secure area with easy access to transportation nodes, but must be protected from the effects of the battlefield to the extent feasible based on the mission, enemy, terrain and weather, troops and support available-time available (METT-T) …
… All locations where detainees are held by U.S. forces must, to the extent feasible based on METT-T, be shielded from the dangers associated with military operations. Commanders should attempt to utilize building-type structures for internment facilities. However, although this may be a preference, there is no prohibition against using less-improved facilities when they offer the best available option for satisfying all legal and policy obligations related to detainee treatment, particularly when use of an improved structure is not feasible. There is no legal requirement to provide detainees with conditions better than those of the U.S. forces executing the detainee operation mission. 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, pp. IV-1–IV-2, IV-4 and IV-6.
In a chapter on “Transport Procedures”, the manual states:
5. Detainee Movement by Maritime Transportation
… [M]aritime transportation … normally … will not be considered as a location for detention (in rare circumstances, temporary maritime detention may provide the best course of action to protect detainees from operational and environmental hazards) … When maritime detention is used, … [it] must meet the requirements of the [1949] Geneva Conventions. 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, p. V-2.
In a chapter on “Transfer or Release from Detention”, the manual states: “As a general rule, detainees should not be transferred closer to the harmful effects of military operations.” 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, p. VII-3.
The manual also states:
Detainee Categories
The DOD [Department of Defense] definition of the word “detainee” includes any person captured, detained, or otherwise under the control of DOD personnel (military, civilian, or contractor employee) … It does not include persons being held primarily for law enforcement purposes except where the United States is the occupying power …
a. Enemy Combatant. In general, a person engaged in hostilities against the United States or its coalition partners during an armed conflict. The term “enemy combatant” includes both “lawful enemy combatants” and “unlawful enemy combatants.”
b. Enemy Prisoner of War. Individual under the custody and/or control of the DOD according to Articles 4 and 5 of the … [1949 Geneva Convention III].
c. Retained Personnel … Personnel who fall into the following categories: official medical personnel of the armed forces exclusively engaged in the search for, or the collection, transport, or treatment of wounded or sick, or in the prevention of disease, and staff exclusively engaged in the administration of medical units and facilities; chaplains attached to enemy armed forces; staff of national Red Cross Societies and that of other volunteer aid societies duly recognized and authorized by their governments to assist medical service personnel of their own armed forces, provided they are exclusively engaged in the search for, or the collection, transport or treatment of, the wounded or sick, or in the prevention of disease, and provided that the staff of such societies are subject to military laws and regulations.
d. Civilian Internee … A civilian who is interned during an armed conflict, occupation, or other military operation for security reasons, for protection, or because he or she has committed an offense against the detaining power. 
United States, Manual on Detainee Operations, Joint Chiefs of Staff, 30 May 2008, pp. I-3–I-5; see also pp. viii and GL-3.
In 2009, the US President issued Executive Order 13492, Closure of Guantánamo Detention Facilities, which stated:
By the authority vested in me as President by the Constitution and the laws of the United States of America, in order to effect the appropriate disposition of individuals currently detained by the Department of Defense at the Guantánamo Bay Naval Base (Guantánamo) and promptly to close detention facilities at Guantánamo, consistent with the national security and foreign policy interests of the United States and the interests of justice, I hereby order as follows:
Sec. 6. Humane Standards of Confinement. No individual currently detained at Guantánamo shall be held in the custody or under the effective control of any officer, employee, or other agent of the United States Government, or at a facility owned, operated, or controlled by a department or agency of the United States, except in conformity with all applicable laws governing the conditions of such confinement, including Common Article 3 of the [1949] Geneva Conventions. The Secretary of Defense shall immediately undertake a review of the conditions of detention at Guantánamo to ensure full compliance with this directive. 
United States, Executive Order 13492, Closure of Guantánamo Detention Facilities, 2009, Section 6.
In 1991, in a diplomatic note to Iraq concerning operations in the Gulf War, the United States advised the Government of Iraq that: “Iraqi prisoners of war … will not be exposed to danger … [and] will be safeguarded against harm during combat operations.” 
United States, Department of State, Diplomatic Note to Iraq, Washington, 19 January 1991, annexed to Letter dated 21 January 1991 to the President of the UN Security Council, UN Doc. S/22122, 21 January 1991, Annex I, p. 2.
In 1991, in a report submitted to the UN Security Council on operations in the Gulf War, the United States stated:
Iraqi authorities have continued to ignore the standards of the Geneva conventions in blatant disregard for international law. They have … deliberately exposed [coalition prisoners of war] to combat danger. 
United States, Letter dated 8 February 1991 to the President of the UN Security Council, UN Doc. S/22216, 13 February 1991, p. 2; see also Letter dated 22 January 1991 to the President of the UN Security Council, UN Doc. S/22130, 22 January 1991.
According to the Report on US Practice, “Articles 4, 5 and 6 [of the 1977 Additional Protocol II] reflect general US policy on treatment of persons in the power of an adverse party in armed conflicts governed by common Article 3” of the 1949 Geneva Conventions. The report also notes: “It is the opinio juris of the US that persons detained in connection with an internal armed conflict are entitled to humane treatment as specified in Articles 4, 5 and 6 [of the 1977 Additional Protocol II].” 
Report on US Practice, 1997, Chapter 5.3.