Ethics and Arms Sales: Operationalizing the Just War Tradition

This essay is part of the #StrategyAndEthics series, which asked a group of academics and national security professionals to provide their thoughts on the confluence of ethical considerations, the development of strategy, and the conduct of war. We hope this launches a debate that may one day shape policy.

In June 2014 the United States government disapproved the sale of twenty-one Bell AH-1 Cobra attack helicopters to Nigeria. The Cobra helicopter case was politically charged due to the Nigerian military’s inability to stem the Boko Haram insurgency. The Nigerian government wanted to acquire Cobra helicopters to field an air-to-ground strike platform and provide its soldiers with close air support. However, the U.S. government denied the sale based on the assessment that the helicopters would not provide any meaningful combat capability to the Nigerian military since the the Nigerian military did not have the technical and logistical capacity to operate and sustain the helicopters. Additionally, the Nigerian government’s poor human rights record influenced the decision to deny the sale. The State Department’s 2014 Human Rights Report for Nigeria states, “In its response to Boko Haram, and at times to crime in general, security services perpetrated extrajudicial killings and engaged in torture, arbitrary detention, mistreatment of detainees, and destruction of property…Security services generally operated with impunity.”[1] The Nigerian government needed help in its fight against Boko Haram and the U.S. had an interest in assisting. However, American policymakers lacked sufficient trust in the Nigerian military to provide them with advanced weaponry and feared the prospect of being implicated in the killing of civilians.

Boko Haram leader Abubakar Shekau (AFP/Boko Haram)

Should the U.S. government provide nations with poor human rights records, weak governance capacity, or militaristic regimes the tools to wage modern war? These types of difficult arms sales cases have the potential to confound the statesmen who make the decision. Fortunately, the rich intellectual heritage of the Just War tradition’s jus ad bellum provides an ethics-based framework to help statesmen assess arms sales cases. The jus ad bellum framework has strategic utility as it compels statesmen to take the long view by forcing them to consider the implications of arms sales and make a judgment about whether the recipient state has the potential to be an enduring security partner.

The Just War Tradition

The Just War tradition prizes peace, but also recognizes that war is a legitimate policy tool under the right circumstances. The philosopher and ethicist James Murphy states, “The Just War tradition is based on the idea that war ought to—and can—be used to establish a proper peace.”[2] The Just War tradition acknowledges that war will lead to suffering, so it provides a set of criteria to help statesmen determine whether the ends of war—namely a better peace—justify the suffering that will accompany it. The Just War tradition’s jus ad bellum framework offers policymakers prudent strategic guidance when deciding whether to transfer arms to a foreign government.[3]

...competent authority, just cause, right intention, reasonable chance of success, last resort, and proportionality...

Given the balance that must be struck between suffering and peace, how can policy-makers leverage the jus ad bellum framework to inform the export of weapons? The jus ad bellum criteria of competent authority, just cause, right intention, reasonable chance of success, last resort, and proportionality can help statesmen assess the strategic implications of arms sales.[4] Policymakers can, and perhaps should, use the jus ad bellum framework to determine whether transferring weapons to another state aligns with accomplishing long-term foreign policy goals such as advancing peace, democracy, human rights, and the rule of law.[5] The competent authority criterion drives statesmen to make a judgment about the quality of the recipient state’s government, which compels policymakers to take the long view by considering the broader strategic implications of the decision to export weapons. The criteria below can help policymakers vet prospective recipients.[6]

  1. Competent Authority: implies the recipient state government has a substantial degree of support from the population, has control of its sovereign territory, and maintains an adequate commitment to the well-being of its citizens
  2. Just Cause: indicates the recipient state has a legitimate reason for acquiring the weapons it seeks and has a history of limiting the use of force to those cases in which legitimate reasons exist
  3. Right Intention: indicates the recipient state intends or is likely to intend to use force to set the conditions for a stable peace
  4. Reasonable Chance of Success: indicates the recipient state government is likely to have a reasonable chance of accomplishing its objectives
  5. Last Resort: indicates the recipient state’s opportunity to accomplish its objectives diminishes to an unacceptable level without military force
  6. Proportionality: indicates the recipient state intends, or is likely to intend, to use force in a manner appropriate for the situation

Policymakers should not only apply the jus ad bellum criteria from the security perspective of the recipient state, but also based on an American moral interpretation of the situation. This approach enables policymakers to conduct arms transfers in a manner consistent with American values, while keeping long-term grand strategic interests in mind. Arms transfer policy should assess the justice of potential sales, and the jus ad bellum criteria provide such a framework.

Reaching back to the Nigeria example, policymakers should ask: Does Nigeria have a competent authority? Does Nigeria have a just cause? And so on. Based on an American interpretation of the above criteria, Nigeria did not meet the competent authority requirement because the government failed to demonstrate an adequate commitment to the wellbeing of its citizens by committing human rights violations in its counterinsurgency campaign against Boko Haram. Though the U.S. had an interest in helping Nigeria fight Boko Haram, authorizing the sale of attack helicopters to the Nigerian military likely would have been counterproductive to American grand strategic interests of advancing human rights and the rule of law. The sale may have had a short-term security benefit by providing the Nigerian military with increased combat capability, but perpetuated long-term patterns of abusive behavior at odds with American foreign policy goals and the establishment of a stable peace.

When considering whether to approve an arms sale request, policymakers must operate under the assumption that the recipient state will (eventually) employ the weapons it has requested and that the U.S. government will not have approval authority over the way they will be used. When policymakers approve a sale, they have indirectly sanctioned the use of force by the recipient of those weapons. The decision to approve a weapons sale indicates policymakers see a strategic benefit for doing so, and trust the recipient state to use the weapons responsibly. Prospective recipients of U.S. weapons should meet all of the jus ad bellum requirements prior to the sale.

The Value of an Ethics-Based Approach

A review of contentious weapons sales cases since 9/11 suggests the jus ad bellum framework can provide an alternative strategic perspective to the arms transfer decision-making process, as shown in the figure below.[7] A qualitative benefit to using the jus ad bellum framework is that it forces policymakers to consider whether the use of force, via arms sales, can help to preserve or establish a lasting peace. The Just War tradition acknowledges the use of force often leads to death and destruction, so it seeks to provide a set of criteria that help statesmen determine whether the ends of war justify the suffering that accompany war. By focusing on the implications of the use of force, the jus ad bellum framework can help those setting foreign policy objectives to identify the legitimate security needs of foreign governments, without obviating the prospects of establishing a stable peace.

Additionally, the jus ad bellum framework can help policymakers manage the tension between competing interests by taking the long view. At times, pressing security interests can clash with long-term foreign policy goals. As the Nigeria case demonstrated, the U.S. government had an interest in eliminating Boko Haram, but providing the Nigerians attack helicopters without addressing Nigeria’s human rights violations could have damaged the prospects for establishing a stable peace and advancing the rule of law. The competent authority criterion of the jus ad bellum framework drives statesmen to make a judgment about the quality of the recipient state’s government and consider how transferring weapons to the recipient state may affect the prospects for accomplishing broader policy goals. Concentrating on governance shifts the focus from pressing security challenges and reframes the debate to consider the long-term viability of the recipient state as an enduring security partner.

However, in order to stay relevant, the jus ad bellum framework should not constrain statesmen from making prudent decisions based on political realities. As Murphy notes, “The application of the jus ad bellum criteria is impossible without giving due weight to the contextual politics.”[8] U.S. arms sales policy has to be flexible enough to permit the government to help allies and partners address their legitimate security needs. A policy that ignored political and security realities would quickly prove irrelevant. As an example of this flexibility, in 2011 the U.S. government approved the $30 billion sale of F-15 precision strike aircraft to Saudi Arabia in an attempt to bolster the Kingdom’s military capacity in an attempt to stabilize the Middle East.[9] However, Saudi Arabia has an authoritarian government and is “a country where women can’t drive, the Quran is the constitution, and beheadings are commonplace.”[10] Strengthening the Saudi government by providing it with advanced fighter aircraft seemed to be at odds with the National Security Strategy goals of advancing democracy and human rights. The challenge for the United States is to develop a policy that permits arms sales to manage pressing security challenges without sacrificing long-term policy goals or strategic interests, and the jus ad bellum framework can help policymakers strike the appropriate balance between politics and ethics for difficult arms transfer cases.

Royal Saudi Air Force F-15S at Red Flag (Defense Industry Daily)


There is no debating the fact that the sale of lethal weapons can lead to suffering. That said, the ethical concerns surrounding international arms sales should meet the criteria outlined in the jus ad bellum framework whenever politically possible. The jus ad bellum framework encourages policymakers to take the long view by considering the broader strategic implications of the decision to export weapons. Though not a panacea, arms transfers that meet the jus ad bellum criteria provide policymakers with some assurance that the recipient state’s government will use the arms in question responsibly, and in a manner that aligns with broader American foreign policy goals. There is inherent risk with each arms transfer, but using the jus ad bellum framework can help reduce some of the uncertainty. In the end, ethics should not be divorced from politics, nor should ethics function as a straitjacket to inhibit reasoned political decision-making.

Rob Arnett is an officer in the United States Air Force. He is currently assigned as a staff officer at the Pentagon. The views expressed are the author's alone and do not represent the official position of the U.S. Air Force, the Department of Defense, or the U.S. Government.

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Header Image: In this Sept. 12, 2007, image, U.S. missiles and an F-16 at the Chiayi air force base in southern Taiwan, 12 Sep 2007. (Sam Yeh/AFP/Getty Images)


[1] United States Department of State, Nigeria 2014 Human Rights Report (Washington DC, [2015]), 1-2.

[2] James G. Murphy, War’s Ends (Washington DC: Georgetown University Press, 2014), 22.

[3] I have intentionally scoped the article to only consider arms sales to foreign states (Arms Export Control Act, Title 22 of US Code), vice non-state actors, rebel groups, etc. Many arms transfers to rebel groups/non-state actors are conducted under covert authorities (Title 50 of US Code) and remain classified. The Just War tradition could arguably apply to non-state actors, but limited authoritative unclassified data precluded further exploration.

[4] Murphy, War’s Ends, 1.

[5] National Security Strategy, Feb 2015.

[6] Murphy, War’s Ends, 37, 69, 92, 139, 159, 180.

[7] Rob Arnett, The Role of Ethics in International Arms Transfers (Unpublished Thesis, School of Advanced Air and Space Studies, June 2016), 21, 33, 48.

[8] James G. Murphy, War’s Ends (Washington, DC: Georgetown University Press, 2014), 22.

[9] CNN, “U.S., Saudi Arabia Agree to $30 Billion Deal for F-15’s,” 29 December 2011,

[10] Rachel Bronson, Thicker Than Oil: America’s Uneasy Partnership with Saudi Arabia (New York, NY: Oxford University Press, 2006), 8.