¹ See generally Vincent Hunt, Fire and Ice: The Nazis’ Scorched Earth Campaign in Norway (2014) (compiling Norwegian narratives from survivors).

² United States v. List & Others (“The Hostage Case”), XI Trials of War Criminals Before the Nuernberg Military Tribunals 757, 1296 (1950).

³ Id. at 764. The 1899 Hague Regulations indicate that it is especially prohibited: “[t]o destroy or seize the enemy's property, unless such destruction or seizure be imperatively demanded by the necessities of war.” Annex, Convention (II) with Respect to the Laws and Customs of War on Land Art. 23g, July 29, 1899, TS 403, 32 Stat. 1803.

⁴ See Bill, Brian J., The Rendulic “Rule”: Military Necessity, Commander's Knowledge, and Methods of Warfare, 2009 Y.B. Int'l Humanitarian L. 119CrossRefGoogle Scholar.

⁵ List, supra note 2, at 1297.

⁶ One of the impugned orders read as follows: “the rule for reprisal measure is: 1 German killed, 50 hostages, 1 German wounded, 25 hostages shot or hanged. . . . According to the severity of the attack 100 hostages will be hanged or shot for each attack against war essential installations.” Id. at 1289–90.

⁷ Id. at 1253.

⁸ Id. at 1318.

⁹ Johansen is careful to distinguish military necessity within IHL from other areas of the law where the concept of necessity makes an appearance, including as a ground for precluding wrongfulness under the international law of state responsibility. See International Law Commission, Articles on Responsibility of States for Internationally Wrongful Acts, Art. 25, UN Doc. A/56/10 (Oct. 24, 2001).

¹⁰ Although Johansen cites regularly from military manuals, including the Department of Defense's Law of War Manual and Norway's equivalent, she demurs to the view of many government lawyers that military manuals should not necessarily be considered either state practice or opinio juris, but rather expressions of policy. See Charles Garraway, The Use and Abuse of Military Manuals, 7 Y.B. Int'l Humanitarian L. 425 (2004) (counseling against reliance upon military manuals as evidence of state practice given their primary operational purpose).

¹¹ Johansen, like most military lawyers, refers to “the law of armed conflict” (LOAC) rather than IHL. This semantic debate signals how contested the placement of the fulcrum between these two imperatives is.

¹² Francis Lieber, General Orders No. 100: Instructions for the Government of Armies of the United States in the Field (Washington, DC: Government Printing Office, April 24, 1863). The Code, while momentous in aim and effect, was premised on reciprocity between “civilized parties,” thus excluding its application to the wars with the Native American populations under the racist ethos of the time (p. 55).

¹³ See Schmitt, Michael, Military Necessity and Humanity in International Humanitarian Law: Preserving the Delicate Balance, 50 Va. J. Int'l L. 795, 796 (2011)Google Scholar; Robert Kolb, The Main Epochs of International Humanitarian Law Since 1864 and Their Related Dominant Legal Constructions, in Searching for a “Principle of Humanity” in International Humanitarian Law 23, 29 (Kjetil Mujezinović Larsen, Camilla Guldahl Cooper & Gro Nystuen eds., 2013) (observing that the concept has “both a positive, expansive, violence-permitting role, and a negative, restrictive, violence-limiting role”).

¹⁴ See Scott Horton, Kriegsraison or Military Necessity? The Bush Administration's Wilhelmine Attitude Towards the Conduct of War, 30 Fordham Int'l L.J. 576 (2006).

¹⁵ In re von Lewinski (von Manstein), in Annual Digest and Reports of Public International Law Cases Year 1949, at 509, 512 (H. Lauterpacht ed., 1955) (“military necessity has already been discounted in drawing up these rules”).

¹⁶ Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I), June 8, 1977, 1125 UNTS 3.

¹⁷ While the United States has declared some Additional Protocol I provisions to constitute customary international law, it has articulated concerns about others, such as the idiosyncratic definition of international armed conflict (Article 1), the absolute rule prohibiting “widespread, long-term and severe damage to the natural environment” (Articles 35 and 55), the more lenient rules on lawful combatancy and distinction (Article 44), the presumption of civilian status (Articles 50 and 52), the ban on reprisals against civilians and civilian objects (Articles 51 and 54), and the heightened protection accorded to works or installations containing dangerous forces (Article 56). See Theodore T. Richard, Unofficial United States Guide to the First Additional Protocol to the Geneva Conventions of 12 August 1949 (2019).

¹⁸ Compare Margaret T. Artz, A Chink in the Armor: How a Uniform Approach to Proportionality Analysis Can End the Use of Human Shields, 45 Vand. J. Transnat'l L. 1447, 1481 (2012) (arguing that adversaries should “uniformly refuse to allow the presence of human shields to impede an attacking party any time” to disincentivize the tactic) with Beth Van Schaack, The Law & Policy of Human Shielding, in Complex Battlespaces: The Law of Armed Conflict and the Dynamics of Modern Warfare 773, 467 (Christopher M. Ford & Winston S. Williams eds., 2018) (arguing that parties should “treat all human shields as civilians when it comes to the calculation of potential collateral damage, unless there is irrefutable proof of willing participation in hostilities”).

¹⁹ Nils Melzer, Keeping the Balance Between Military Necessity and Humanity: A Response to Four Critiques of the ICRC's Interpretive Guidance on the Notion of Direct Participation in Hostilities, 42 J. Int'l L. & Pol. 831 (2010).

²⁰ Ryan Goodman, The Obama Administration and Targeting “War-Sustaining” Objects in Noninternational Armed Conflict, 110 AJIL 663 (2016).

²¹ See Report of the Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions, Christof Heyns, UN Doc. A/HRC/23/47 (Apr. 9, 2013) (questioning whether lethal autonomous robotics will be able to properly assess military necessity and other elements of IHL).

²² In this regard, the book focuses on legal restraints upon commanders’ practical freedom of maneuver rather than on the political, policy, ethical, or moral restraints that might impose heightened restrictions on a fighting force—e.g., through rules of engagement—the “should we” query as opposed to the “can we” query.

²³ SC Res. 1973 (Mar. 17, 2011).

²⁴ See Jefferson D. Reynolds, Collateral Damage on the 21st Century Battlefield: Enemy Exploitation of the Law of Armed Conflict, and the Struggle for a Moral High Ground, 56 A.F. L. Rev. 1, 34 (2005).

²⁵ Incidentally, the proverbial commander can exist at multiple levels along a military chain of command and is not necessarily limited to a senior figure providing strategic direction to subordinates. In particular, Johansen notes that “[t]he duty to cancel or suspend an attack may, in principle, apply all the way down to the individual soldier” (p. 84, citing Additional Protocol I at Art. 57(2)(b)).

²⁶ See Yuval Shany, Toward a General Margin of Appreciation Doctrine in International Law?, 16 Eur. J. Int'l L. 907 (2016).

²⁷ See Yutaka Arai-Takahashi, The Margin of Appreciation Doctrine and the Principle of Proportionality in the Jurisprudence of the ECHR (2002).

²⁸ See Ethiopia-Eritrea Claims Commission, Permanent Court of Arbitration, at https://pca-cpa.org/ru/cases/71.

²⁹ Dep't of Def., Conduct of the Persian Gulf War: Final Report to Congress (1992).

³⁰ See Nobou Hayashi, Requirements of Military Necessity in International Humanitarian Law and International Criminal Law, 28 Boston Univ. Int'l L.J. 39 (2010).

³¹ See N.C.H. Dunbar, Military Necessity in War Crimes Trials, 29 Brit. Y.B. Int'l L. 442 (1952).

³² See Rogier Bartels, Discrepancies Between International Humanitarian Law on the Battlefield and in the Courtroom: The Challenges of Applying International Humanitarian Law During International Criminal Trials, in Armed Conflict and International Law: In Search of the Human Face 339 (Mariëlle Matthee, Brigit Toebes & Marcel Brus eds., 2013).

³³ See, e.g., Prosecutor v. Gotovina, Case No. IT-06-90-T, Judgment (Int'l Crim. Trib. for the Former Yugoslavia Apr. 15, 2011) (establishing an unworkable “margin of error” for attacks); Prosecutor v. Bemba, ICC-01/05-01/08 A, Judgment on the Appeal of Mr. Jean-Pierre Bemba Gombo against Trial Chamber III's “Judgment Pursuant to Article 74 of the Statute” (June 8, 2018) (acquitting the defendant on dubious reasoning about the liability of remote commanders).

³⁴ The ICTY Office of the Prosecutor has noted that the proportionality determination may differ “depending on the background and values of the decision maker. It is unlikely that a human rights lawyer and an experienced combat commander would assign the same relative values to military advantage and to injury to noncombatants. Further, it is unlikely that military commanders with different doctrinal backgrounds and differing degrees of combat experience or national military histories would always agree in close cases.” Office of the Prosecutor, International Criminal Tribunal for the former Yugoslavia, Final Report to the Prosecutor by the Committee Established to Review the NATO Bombing Campaign Against the Federal Republic of Yugoslavia, para. 50 (2000), available at https://www.icty.org/x/file/Press/nato061300.pdf.

³⁵ See, e.g., Amicus Curiae Submission of the Government of the United States of America Concerning Certain Arguments Made by Counsel for the Accused in the Case of The Prosecutor of the Tribunal v. Duško Tadić, Case No. IT-94-1-T (July 17, 1995).

³⁶ David Scheffer, The Self-Defeating Executive Order Against the International Criminal Court, Just Security (June 12, 2020).

³⁷ Annyssa Bellal, The War Report: Armed Conflicts in 2018, at 19 (Geneva Academy of International Humanitarian Law and Human Rights 2018) (noting that fifty-one out of sixty-nine conflicts surveyed were noninternational armed conflicts).

³⁸ See Beer, Yishai, Humanitarian Considerations Cannot Reduce War's Hazards Alone: Revitalizing the Concept of Military Necessity, 26 Eur. J. Int'l L. 801 (2015)CrossRefGoogle Scholar.

³⁹ Hill-Cawthorne, Lawrence, The Role of Necessity in International Humanitarian and Human Rights Law, 47 Isr. L. Rev. 225 (2014)Google Scholar.

⁴⁰ ICRC, Interpretive Guidance on the Notion of Direct Participation in Hostilities Under International Humanitarian Law 1044–45 (2009)

⁴¹ But see The Public Committee Against Torture in Israel, et al. v. Israel, HCJ 769/02, para. 40 (Dec. 13, 2006).

⁴² Corn, Geoffrey S., Blank, Laurie R., Jenks, Chris & Jensen, Eric Talbot, Belligerent Targeting and the Invalidity of a Least Harmful Means Rule, 89 Int'l L. Stud. 536 (2013)Google Scholar.

⁴³ The Obama administration, for example, implemented a set of standard operating procedures for deploying lethal and nonlethal force against terrorist targets that prioritized the capture of terrorist suspects and allowed lethal action only if there was near certainty that the action could be taken without injuring noncombatants. See, e.g., Presidential Policy Guidance, Procedures for Approving Direct Action Against Terrorist Targets Located Outside the United States and Areas of Active Hostilities (May 22, 2013), at https://www.justice.gov/oip/foia-library/procedures_for_approving_direct_action_against_terrorist_targets/download.

⁴⁴ Ryan Goodman, The Power to Kill or Capture Enemy Combatants, 24 Eur. J. Int'l L. 819 (2013).

⁴⁵ See Bartels, Rogier, Dealing with the Principle of Proportionality in Armed Conflict in Retrospect: The Application of the Principle in International Criminal Trials, 46 Isr. L. Rev. 271 (2013)Google Scholar.

⁴⁶ Carl von Clausewitz, On War (2008). On War was originally, and posthumously, published in 1832.

⁴⁷ Farley, Benjamin R., Enhanced Interrogation, The Report on Rendition, Detention, and Interrogation, and the Return of Kriegsraison, 30 Emory Int'l L.J. 2019, 2023 (2015)Google Scholar.