The Army Lawyer | Issue 2 2021View PDF

null Book Review: Re-Thinking International Law Advice

Book Review

Re-Thinking International Law Advice

A JA’s Guide to How to Do Things with International Law

This year marks the 75th anniversary of an event consequential to the practice of military law—the International Military Tribunal (IMT) at Nuremberg. While the IMT, held from November 1945 to October 1946, was reserved for the highest-ranking German leaders, subsequent tribunals held over the preceding years would carry forward the IMT’s precedence and legacy in determining how international law principles would apply to individual conduct. Specifically, in the trial of Wilhelm List and Others before the United States Military Tribunal,1 high-ranking German army officers were charged with having practiced reprisal killings while occupying Greece, Yugoslavia, Albania, and Norway. The war crimes court had to judge whether military necessity, an international humanitarian law principle, was a viable defense.2 It was the German officer defendants who invoked the principle of military necessity to justify their killing of innocent civilians and destruction of towns and villages throughout the occupied territories.3 They claimed that this international humanitarian law principle, developed for mitigating harm to civilians in wartime, had given them authorization to kill. The judges concretely dismissed such a defense, stating, “[m]ilitary necessity or expediency do not justify a violation of positive rules. International [l]aw is prohibitive law.”4

Ian Hurd’s How to Do Things with International Law proposes a theory that introduces nuance to the war crime court’s statement that “[i]international law is prohibitive law” and provides a concise theory challenging this conventional view. With support from a thorough examination of controversial cases related to national security, such as torture and targeted killings by drones, Hurd proves that international law is not a fixed set of rules applied consistently to “prevent the misuse and abuse of political power,”5 but rather is a strategic tool used to accomplish national interests.6 Hurd’s point is simple: “in practice, law and politics are closely intertwined, even inseparable,” and, therefore, “[i]nternational law is political because it is useful.”7 The idea that international law is political is controversial because the contemporary view is that international law enforces the rule-of-law ideology and replaces self-interested politics in international relations. The idea that international law is a tool to be used also offers an insightful way of thinking about how lawyers, such as judge advocates (JAs), advise their clients. Hurd’s argument gives a unique perspective on the practice of international law that is relevant to JAs as they balance the expectations of their clients with the challenges of future conflict.

The intent of this review is to summarize Hurd’s theory in a manner that is easily digestible for JAs and, as a result, causes them to re-think how to provide international law advice. To accomplish this goal, one must first consider a brief explanation of Hurd’s primary premise—that international law does not enforce a rule-of-law ideology, but is a tool used to achieve strategic, political ends. Then, discussion turns to key takeaways from Hurd’s examination of three cases that effectively “demonstrate[] law’s capacity to enable, permit, and constitute state action”8: 1) self-defense and the use of force; 2) use of new weapons, such as drones; and 3) torture. Finally, this review discusses ways in which Hurd’s book may cause JAs to re-think their roles as legal advisers and how they provide principled counsel under his theory of international law.

International Law Is a Tool

Instead of interpreting the law in a way that restricts and constrains the client, Hurd argues that states use the law to justify and gain legitimacy for action that would otherwise not be acceptable. Historically, justification of state action relied on sources such as “divine right, economic exigency, self-preservation, ethnic self-determination, claims to modernity, and scientific racism.”9 While he leaves the how and why of the transition away from these sources to other scholars, Hurd adopts what seems to be the position of international legal and relations experts—that the primary source of legitimacy in modern international relations is the law. Because there is currently “widespread belief in rule-of-law ideology, whereby acting lawfully is a determinant of state legitimacy,” states are now incentivized to “frame their choices and goals within legal categories.”10 Therefore, because state legitimacy is now a matter of legality, the incentive to legalize issues makes the role of lawyers more important, but potentially at the cost of miscategorizing the issue. By solving every problem with a legal answer, Hurd convinces the reader that this legalization of international relations can ultimately dilute the “morality or strategic wisdom” 11 of our national security decision-making.

Hurd’s book also serves as an excellent companion to any study of how law interacts with national security and military operations. “Lawfare,” a term well known to JAs, is a state’s practice of “us[ing] international law to discredit its rivals in pursuit of its sovereign interests,”12 or “the use of law as a weapon of war.”13 Hurd believes that “[l]awfare is better seen as the typical condition of international law.”14 Although his book is not a manual for its practical exercise, it does provide an intellectual foundation of lawfare by showing clearly how “international law and international power cannot be separated.”15

Rule-of-Law Is Not the Rule

Fully grasping Hurd’s heady theory requires the reader to understand the distinction he makes between the rule-of-law ideology in domestic law and the lack of it in international relations. Put simply, if international law is a tool, then the rule-of-law ideal cannot exist. This is an important concept to grasp because it considerably alters how the reader thinks of international law’s purpose and power. A system based on the rule-of-law ideology has three characteristics: 1) “knowability and stability”; 2) “individuals and governments are equal under the law”; and 3) the “law is applied consistently across cases” by independent judiciary.16 Hurd expertly argues, however, that these ingredients cannot be found within international relations. After the devastation of World War II, the victors—led by the United States—attempted to transplant a liberal, rule-of-law ideology that the Founding Fathers instituted at home to the international stage. With the United Nations (U.N.) Charter as its cornerstone, war would be illegal, disputes would be resolved through diplomatic deliberation, and a global respect for the rule of law would bring an everlasting peace. This ideal has not become reality. Hurd’s insightful analysis walks the reader through why it has not.

First, international law fails to “offer this stability and clarity”17 because states, unlike citizens at home, can change the legality of their conduct by either signing a treaty, modifying an existing treaty, or withdrawing from a treaty altogether. Simply put, the state has the power to determine what rules to follow and, thus, what is legal and what is not. Next, if “diminishing the absolute power of government is, of course, the objective of the rule of law,”18 then this objective fails. Although the Security Council under the U.N. Charter has the perceived “decisive governing authority over the member states,”19 Hurd shows otherwise.

To prove this, he points out how the “Council’s relationship to international law has long been debated,” and how the Court of Justice of the European Union affirmed that the “Council is a political rather than a legal organ” because it does not respond to violations of international law.20 Last, for the reader that believes in the existence of an independent judiciary that enforces international law consistently—which is the third ingredient to a rule-of-law-based system—Hurd proves them wrong again. There is no international compulsory jurisdiction. In fact, the International Court of Justice’s (ICJ) own statute states that ICJ decisions “have no binding force except between the parties and in respect of that particular case.”21 If there is compulsory jurisdiction in international relations, it is only because the state consented to it. Moreover, the state can just as easily withdraw that consent. Hurd’s logic and analysis in applying the three ingredients found in the domestic rule-of-law ideology to international relations forces the reader to reconsider international law’s purpose and power. By proving that rule-of-law ideology does not exist in international relations, Mr. Hurd lays the foundation to better understand the causes of the following cases.

War Still Happens

Most military professionals are familiar with some translated version of Carl von Clausewitz’s famous proclamation that “war is simply a continuation of political intercourse, with the addition of other means.”22 Whether one views Clausewitz’s statement as cynical or as an enlightened reflection of warfare in a past era, the contemporary view is that, with aggression now outlawed,23 war has become a legal matter. As Hurd illustrates for the reader, the vagueness of post-war international law and the legalization of international relations has likely started more conflicts than it has prevented. “By defining what wars are lawful and in bending to the changing interests of powerful states, the ban on war constitutes a resource that states use to legitimate their use of force.”24 To those readers that may perceive international law as “an improvement on the ‘bad old days’ when the decision to go to war was purely political and unconstrained by legal obligations,”25 Hurd offers an effective counter-claim. He argues that, in reality, “[g]overnments are freer to use force under the interpretation that prevails today than they would be if the rules were read a more formal way as black-letter law.”26 As an example, because of what he calls the “juridification”27 of power and politics, the self-defense exception “has come to refer to the defense of the interests of the state, not of its physical borders and territory.”28

The simple fact is, despite the prohibition of war since it was outlawed by the U.N. Charter, states continue to fight each other and spend billions of dollars on their armed forces. For example, the United States has “gone to war” in Korea, Vietnam, Lebanon, Granada, Panama, Iraq (twice), Afghanistan, and Syria since war was prohibited in 1945.29 His examination of the legalization of self-defense clearly shows how international law fails to constrain state action. Instead, the law of self-defense has become a tool used to go to war, often forcing states to justify their actions using legal concepts when politics or national interest are the obvious reason.

Filling the Gap

Hurd next examines how international law is such a powerful tool that it is used to fill the gaps where no law actually exists. Specifically, he provides insight into how and why states rely on legal concepts to justify the use of new weapons when there are not explicit regulations in force. Hurd’s analogy of drones to nuclear weapons helps illustrate his point. “With nuclear weapons in the twentieth century and drones in the twenty-first, states and their advisers were confronted with policy possibilities that were not foreseen by the then-existing international rules on warfare.”30 Instead, however, of articulating policy reasons to gain legitimacy for the use of new weapons, states have used international law to fill the justification gap. His review of the ICJ’s Nuclear Weapons advisory opinion is insightful. When the ICJ was asked, “Is the threat or use of nuclear weapons in any circumstances permitted under international law,”31 the Court found that nuclear weapons were, in fact, lawful. How they arrived at that conclusion, however, supports Hurd’s theory and is especially useful for JAs. The dissent’s opinion centered on the application of the 1927 Lotus decision, which developed the principle that “where no law exists, states are free to act as they wish.”32 Therefore, because there was no treaty banning nuclear weapons, their existence was lawful. The majority in the Nuclear Weapons advisory opinion, however, took the logic further. In an effort to “search for ways that state behavior might be connected with legal obligations,”33 the Court determined that “if [nuclear weapons] were illegal, then this is tantamount to a death sentence for the law abiding state.”34 Therefore, because it would be “inconceivable that the governments of the world intended to make nuclear weapons illegal,” they must be lawful.35 Hurd’s takeaway is that the ICJ “link[ed] state interests and self-defense in determining international legality.”36

Applying this takeaway to drones, the reader can see why the debate of their use centers on legal justifications when, in fact, no law regulating them actually exists. “As with nuclear weapons before them, it is not self-evident which, if any, legal rules apply or how they should be applied to this new weapon.”37 As Hurd argues, this proves the power of international law as a tool. If the justification for their use was simply that they are cheaper to maintain, more expendable than a pilot, and are just as effective in killing individuals as a Navy SEAL team, then legitimacy would likely be harder to gain. Instead, the United States has focused on legal concepts—such as the characterization of the conflict or compliance with treaty—and customary laws of armed conflict to gain legitimacy, when really the reason is likely more aligned with politics and national interest. Thus, because international law is a tool, the legality of drones “ends up derivative of state security.”38 Hurd’s examination of the legalization of the drone debate is strong evidence in support of his theory and provides a helpful example for JAs, many of whom have practical experience in this area. Whether down-range or in the classroom, Hurd forces the reader to re-think and re-frame the issue by asking why the United States uses legal concepts to justify their use of drones when there is no existing law regulating their use. After reading his book, the answer is clear: international law is a tool to justify action, not a set of rules that constrain it. As JAs confront how to advise on new technologies, such as artificial intelligence and autonomous weapons, Hurd’s argument may help to discern unforeseen legal and policy challenges.

If It Looks Like a Duck

Hurd’s final illustrative case shows just how powerful a tool international law can be. Overcoming universal acceptance on the prohibition on torture, the United States was able to justify its enhanced interrogation program by framing it, not as a moral or national security issue, but as a legal one. Many JAs are aware of the controversy surrounding the military’s disturbing interrogation techniques during the early stages of the war on terrorism and the efforts of senior military lawyers who attempted to prevent them on the basis that they constituted torture.39 That many senior Defense leaders were on the same page regarding the illegality and immorality of torture, yet the United States still legally justified waterboarding, sleep-deprivation, face slapping, and other disturbing techniques, goes to show that Hurd’s theory has practical and damaging consequences. “Thus, eschewing moral and strategic concerns, lawyers can argue about whether waterboarding is or is not torture as a legal matter.”40 It is unlikely the United States would have ever been successful in getting the interrogation program off the ground if its justification was simply grounded in matters of national security. Instead, as Hurd thoroughly explores, international law was used as a tool to re-frame—and thus justify—state action. That the interrogation program was so controversial at the time, but able to exist for as long as it did under the cloak of legality, further proves his insightful argument of how powerful a tool international law can be.

What This Means for JAs

Hurd’s theory that international law is a tool, not a constraint, is instructive and relevant to the practice of JAs in three major ways: 1) how legal questions are answered; 2) how the concept of principled counsel applies in this legal framework; and 3) how the military legal community contributes to the legalization of international relations.

Lawyers are naturally inclined to say “no” because they are trained and educated to view the law as prohibitive in nature. Unless the client understands, and fully supports the lawyer’s role to keep them out of jail, there is often an inherent tension between the lawyer and the client when lawyers are seen as obstacles to progress. Nowhere is this tension more exacerbated than in the military profession, where commanders are trained from the earliest phases of their careers to be aggressive leaders of action. Thus, there is significant time and energy spent on the development of JAs. The approach JAs are instructed to take is that, while it may be easier to give a “no” answer, the job is to get clients to the “right” answer. Hurd’s theory that international law is not prohibitive law, but instead is a strategic tool, potentially alters how JAs provide legal advice. Often, commanders want the clear legal answer. However, as Hurd has shown, there often is not one. His point regarding international law’s lack of stability and clarity means, when advising commanders on matters related to international law, “a clear rule does not mean a clear obligation.”41 Therefore, providing the “legal” answer requires the JA to be innovative, both in how they frame their advice and how they provide value to the staff in helping to maintain or increase the commander’s “maneuver space.”

This leads to the second practical application. How does Hurd’s theory, which clearly shows that law and policy are intertwined, affect principled counsel? Principled counsel is “professional advice on law and policy grounded in the Army Ethic and enduring respect for the Rule of Law, effectively communicated with appropriate candor and moral courage, that influences informed decisions.”42 A critical component to principled counsel is distinguishing between legal advice and policy advice. Judge advocates must ensure that the client knows which type of advice they are receiving. Hurd suggests, however, that this is impossible in international law because there is no distinction. This argument requires the JA to grasp the political, moral, and strategic consequences of the problem, not just its legal aspects, when providing principled counsel. If the JA’s advice is a tool to achieve an objective, then they have a professional obligation to understand fully what the objective is. This requires the JA to take a deliberate and focused approach to their individual development, as both a staff officer and military professional.

Finally, Hurd’s theory should force JAs to reflect on how the military legal community contributes to the legalization and “juridification” of national security issues. It is well known that modern military commanders rely heavily on their JAs to navigate complex situations. In fact, the U.S. Army requires such reliance. “If the question is more complex, seek legal counsel.”43 As Hurd shows with his examination of nuclear weapons and drones, the contemporary approach to addressing novel concepts is to legalize the issue. Whereas adherence to legal obligations has its place in developing solutions to these matters, it is important to consider that the solution may be framed in legal concepts because—in today’s international security environment—legality provides the most legitimacy.

The role then of the national security lawyer, and specifically the JA, may very well be influenced by the legalization of non-legal problems. Whether this reliance on the use of international law as a tool will benefit or constrain the United States in the future is worth considering. Will legality continue to be the measure of legitimacy in an era of Great Power competition when China and Russia blatantly ignore legal norms? Will military operations still be constrained by self-imposed policy and legal restrictions, which were required to gain legitimacy in fighting a counterinsurgency, when the United States transitions its focus to winning the next world war? After all, in winning World War II and defeating fascism on two continents, General Patton or Admiral Nimitz did not rely on their JAs in ways that commanders do today.44


How to Do Things with International Law provides an insightful perspective on the power of international law, especially when it comes to matters of national security and military operations. Whereas some of the logic, at times, may be dense, Hurd’s argument that international law is a tool is clearly proven after reflecting on the three cases he thoroughly examines. Although war is illegal under the U.N. Charter, states continuously use international law to justify conflict. Although international law is silent on the use of drones to conduct targeted killings, states justify their use with existing legal concepts. Finally, although there was no question regarding the illegality of torture, states used international law to justify activities that many deemed morally repugnant and harmful to national interests. As the justices of the war crimes trials dictated three-quarters of a century ago, these three well-known cases illustrate masterfully Hurd’s argument that international law is not prohibitive law, but a tool to achieve national interests. For the JA providing principled counsel in international law, and seeking to be a valuable force multiplier on any staff, Hurd’s book is a must-read. TAL

LCDR Harbin is a joint legal observer/trainer on the Joint Staff in Suffolk, Virginia.


1. The trial of Wilhelm List and Others before the United States Military Tribunal is also known as the Hostages Trial.

2. U.N. War Crimes Commission, 8 Law Reports of Trials of War Criminals 34–92 (1949).

3. Id.

4. Id. at 66.

5. Ian Hurd, How to Do Things with International Law 21 (2017).

6. Id. at 47.

7. Id. at 48.

8. Id. at 11.

9. Id. at 54.

10. Id. at 48.

11. Id. at 51.

12. Matthias Vanhullebusch & Wei Shen, China’s Air Defense Identification Zone, 16 China Rev. 121, 123 (2016).

13. Colonel Charles J. Dunlap Jr., Law and Military Interventions: Preserving Humanitarian Values in 21st Conflicts 2 (2001), (a paper prepared for presentation at the Humanitarian Challenges in Military Interventions Conference at the Kennedy School of Government, Harvard University, in Washington, D.C., on 29 November 2001).

14. Hurd, supra note 5, at 11.

15. Id. at 9.

16. Id. at 23–24.

17. Id. at 32.

18. Id. at 24.

19. Id. at 39.

20. Id. at 40.

21. Id. at 43.

22. Carl von Clausewitz, On War 731 (Michael Howard & P. Paret eds., 1993) (1832).

23. See U.N. Charter art. 2, 4 (obligating all states to “refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations”).

24. Hurd, supra note 5, at 59.

25. Id. at 58.

26. Id. at 59.

27. Id. at 65.

28. Id. at 73.

29. Barbara Salazar Torreon, Cong. Rsch Serv., RS21405, U.S. Periods of War and Dates of Recent Conflicts (2020).

30. Hurd, supra note 5, at 84.

31. Id. at 85. See Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 I.C.J. 6 (July 8).

32. Hurd, supra note 5, at 87. See Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996 I.C.J. 16 (July 8) (citing The Case of the S.S. Lotus (France v. Turkey), 1927 P.C.I.J. no. 9 (Sept. 7).

33. Hurd, supra note 5, at 88.

34. Id. at 89.

35. Id.

36. Id.

37. Id. at 91.

38. Id. at 92.

39. See generally Major General (Retired) Thomas J. Romig, The Thirty-First Charles L. Decker Lecture in Administrative and Civil Law, 221 Mil. L. Rev. 257 (2014). See also Alberto Mora, The First Thomas J. Romig Lecture in Principled Legal Practice, 227 Mil. L. Rev. 443 (2019).

40. Hurd, supra note 5, at 51.

41. Id. at 33.

42. TJAG and DJAG Sends, Vol. 40-16, Principled Counsel—Our Mandate as Dual Professionals (9 Jan. 2020).

43. U.S. Dep’t of Army, Doctrine Pub. 6-22, Army Leadership and the Profession para. 2-22 (31 July 2019) (C1, 25 Nov. 2019).

44. See Frederic L. Borch, Judge Advocates in Combat: Army Lawyers in Military Operations from Vietnam to Haiti (2001) (exploring the development of the judge advocate’s role in providing operational law advice and noting what began during the Vietnam War “came to full bloom in the 1990s”).