2. A Theory of Endless War and its Applicability in Yemen

Labeling the counterterrorism war in Yemen an endless war requires defining endlessness. This section defines “endless war” and presents a framework for the analysis that follows. It defines key terms used throughout this report and explains why the combination of jihadist weakness, expansive and/or unclear American objectives, and poor war termination planning promoted endlessness in the war in Yemen and America’s counterterrorism wars more broadly. The definitions and framework used here were first presented and are described in greater detail in the author’s prior report, Defining Endless Wars. ¹

Some commentators argue that “endless war” is a meaningless political talking point, a conclusion this report rejects.² This report defines war as having an endless character when two conditions exist: The first condition is that a belligerent adopts objectives that it lacks the capability to achieve; the second condition is that despite the inability to achieve its objectives, the belligerent is also not at risk of being defeated or otherwise denied access to the battlefield and thus the ability to pursue its objectives remains.

Endlessness is best assessed by evaluating objectives and the balance of power in a war—the two core facets of its definition. However, other, more easily compared markers can inform assessments of whether a war has taken on an endless character. War duration is a particularly useful marker. But because duration is not dispositive as to whether a war is an endless war, it must be followed up with further analysis to determine whether a war has an endless character or is simply lengthy in duration.³

The counterterrorism war in Yemen has taken on an endless character. While the United States’ objectives have varied over time, the United States has sought objectives like the defeat and destruction of al-Qaeda in Yemen, eventually known as Al-Qaeda in the Arabian Peninsula, that appear to be beyond the capability of the United States to achieve. At the same time, AQAP is not capable of defeating the United States. Nor can AQAP deny the United States the capability to conduct strikes inside Yemen. There is little evidence that these conditions will soon change.⁴

When not pursuing unlimited objectives of defeating and destroying AQAP, the United States has sought to degrade and disrupt AQAP’s activities, particularly, to deny it territory, but it has rarely framed its limited objectives in a way that envisions and prepares for an end to the war. As a result, objectives that might have been achievable, have also proven beyond the United States’ capabilities.

The war’s long duration bolsters the claim that it has taken on an endless character. The United States has waged its counterterrorism war in Yemen for more than 12 years; more than 19 years, if one begins counting with the first strike in 2002.⁵ This means the war has gone on for about as long as the U.S. war in Vietnam, a case that was described as endless in contemporaneous discussions.⁶

While there has been some discussion of the war in Yemen as an endless or forever war, debate has focused primarily upon the U.S. support for the Saudi-led war against the Houthis and not the counterterrorism war. Legislative efforts to end U.S. support for the Saudi-led coalition’s war against Houthi rebels in Yemen have tended to exclude America’s counterterrorism strikes from their purview.⁷ Although the two wars are intertwined, this report focuses upon the U.S. counterterrorism war on AQAP and other jihadist groups.

Four factors have been particularly important in generating endlessness in the United States’ counterterrorism wars.⁸ They are:

1. The weakness of jihadist groups. Jihadist groups are incapable of militarily defeating the United States, either by destroying it, or by denying it access to the battlefield. Were jihadists capable of posing such a threat, America’s wars might end with jihadists achieving victory against American wishes.⁹ As the United States’ jihadist enemies lack such capabilities, the United States is the primary power capable of determining the location and character of its wars. Jihadists can use violence to influence and coerce that decision process but cannot militarily defeat the United States.

Moreover, most jihadist groups do not pose threats that force stark choices for the United States.¹⁰ Instead, the threat has tended to be similar to such accepted risks as industrial accidents or people dying in bathtubs.¹¹ Even on the battlefield far from the United States, the U.S. way of war insulates the American military from violence, imposing a radical asymmetry.¹² The level of threat that jihadist groups pose to the U.S. homeland can be placed on a spectrum ranging from a very high level of an existential threat through a medium level of a group incapable of taking territory but capable of highly disruptive campaigns of repeated attacks to a very low level where a group has not demonstrated a capability to direct attacks inside the United States (See Table 1).

2. The United States’ expansive and often unlimited objectives. The United States has tended to select expansive objectives—most notably, unlimited objectives (objectives that seek the total destruction and defeat of the enemy).¹³ Even where the United States has chosen limited objectives (objectives that pursue something other than total defeat), it has often selected difficult-to-achieve objectives that still involve expansive visions of transforming governance. Where the United States has selected limited and disruptive objectives regarding specific threats, it has often found its objectives achievable but unsatisfying, revealing the continued existence of limited but transformative or unlimited objectives. In evaluating the existence of this factor, it is useful to identify whether a war’s objectives are unlimited, limited and transformative, or limited and disruptive, which tend to vary in their difficulty (See Table 2).

3. The United States’ pursuit of unclear or unstable objectives. The United States has failed to maintain stable and clear objectives in its wars. It is difficult to end a war if one cannot determine whether one’s objectives were accomplished because they were never clearly stated or because new objectives emerge as older objectives are accomplished.¹⁴ One way to measure the extent to which a war’s objectives are clear and stable is to look at whether the government provides a consistent public explanation of what it desires the war to produce, which can be evaluated on a spectrum from Very Clear to Very Unclear (See Table 3).

4. The United States’ lack of preparation and planning for war termination. The United States has also often failed to plan for war termination.¹⁵ As a result, the U.S. may appear to have achieved its objectives, but only insofar as the U.S. continues to apply military force. A failure to adequately develop plans for war termination can result in the U.S. failing to exit or exiting only to return later.¹⁶

Efforts to terminate the United States’ counterterrorism wars pose a particular set of challenges. A belief in the importance of achieving unlimited or decisive military defeat of enemies has stunted planning for war termination.¹⁷ Christopher Kolenda argues that the Department of Defense “has no definition or doctrine for this seemingly critical aspect of war. Options other than decisive victory do not exist in the national security lexicon.”¹⁸ Traditionally, a peace agreement is the gold-standard of war termination whether achieved after a decisive military triumph or as a result of negotiation.¹⁹ This is for good reason, and the United States should not automatically dismiss negotiation with even its most radical terrorist enemies.²⁰

However, governments are loathe to negotiate peace agreements with groups that embrace terrorism as a tactic, in part because the tactic contributes to a perception—one that is not necessarily false—that such groups have maximal aims and won’t actually end their use of violence.²¹ Moreover, the decentralized character of many of the United States’ current rivals means that, even if a deal were struck, it might not be enforceable. War termination via a peace deal between the United States and al-Qaeda is thus unlikely.

This does not mean war termination is impossible. The extensive focus on a peace agreement as the only way to terminate a war reflects the peculiar role that wars between continental European states, who could not effectively deny their rivals access to the battlefield, played in generating conceptions of war termination.²² In contrast, the United States, like many other maritime powers, is capable of effectively denying an enemy the ability to turn its own territory into a battlefield. Kolenda terms such an approach transition as contraposed to decisive victory, in which the enemy is either militarily annihilated or surrenders, and negotiated outcome, in which no power surrenders but both come to an agreement to end the war (or at least direct hostilities).²³ In the absence of a peace agreement, the United States can terminate a war by handing responsibility for security over to a partner or other authority.²⁴

Some contend that such a handover is not a true end to the war, arguing that al-Qaeda will continue to pursue its “endless jihad” regardless of U.S. action.²⁵ This, however, is a misreading of what war is. War, at least in most Western philosophical traditions, requires some level of reciprocal threat or implied agreement to combat in the form of war.²⁶ If one side does not fight and another does, that is traditionally viewed as murder, massacre, or other forms of one-sided violence.²⁷ The United States can also bolster its war termination capabilities by improving its already strong defensive measures, including law enforcement and intelligence work, and its efforts to address the systemic crises and grievances that empower jihadist groups.²⁸

A handover of responsibility combined with clear renunciation of a war footing is likely to be the nature of war termination in the United States’ counterterrorism wars. The extent of development of war termination plans can thus be assessed as being at a low, medium, or high level depending on the amount of preparation for such a handover and the ability of the newly responsible actor to maintain a level of security that does not depend on the continued use of direct American force or a continued war-footing that enables rapid re-escalation without renewed debate and the authorization of a new war (See Table 4).

By focusing on the interaction between achievability and clarity of objectives while assuming a context in which the enemy is incapable of ending the war on its own terms, we can identify four distinct types of endless war (See Table 5). No war is likely to fall entirely within any of these types. However, positing these types warns against an overemphasis on any single policy approach that might be useful in ending some wars but not others.

Type 1: The first type are wars that take on an endless character because the government does not set stable and clear objectives and is also not capable of achieving the objectives it sets out because they are so expansive. Efforts to bring such wars to an end require both clarifying the objectives and ensuring that the newly clarified objectives are achievable. Efforts that prioritize only one strand of policy will simply move the war into a different type of endlessness.

Type 2: The second type are wars where the government is clear about what objective it seeks but has selected an objective that is so expansive as to be unachievable. In these wars, endlessness is primarily driven by expansive objectives, requiring the government to limit what it seeks in order to end the war. In contrast, efforts to improve the clarity of objectives, for example by expanding transparency, will have little success as a tool for bringing such wars to an end because their endlessness is not rooted in unclear or opaque objectives but in the willful decision to pursue difficult-to-achieve objectives. A focus on increasing transparency and clarity as the leverage point in such wars risks undermining efforts to end the war by deemphasizing questions about the political objective in favor of legalistic criticism.²⁹

Type 3: The third type are wars where the government does not know what its objectives are and often shifts objectives, but those shifting objectives are achievable. In such a war, the key leverage point for ending the war is clarifying what the United States’ true objectives are. Whereas in a Type 2 endless war, a focus on transparency is unlikely to bring an end to war and can risk prolonging it, in this kind of endless war, it is essential while focusing criticism on the achievability of specific ends is likely to lead to poor analysis.

Type 4: The fourth type occurs when the government has achievable and clear objectives. Under such conditions, endless war should be rare. However, endlessness may still emerge for other reasons. For example, the war might take on an endless character if the government fails to adequately prepare for and develop war termination plans.³⁰

This report assesses the Yemen war to be somewhere between a Type 1 endless war (with endlessness driven both by a failure to clearly define objectives and by the presence of unachievable expansive objectives) and a Type 3 endless war (with endlessness driven by a lack of clear and stable objectives but where objectives—when stated—tend to be achievable).

The character of endlessness in Yemen can be illuminated by comparison with the counter-ISIS war (See Table 6). The counter-ISIS war is best understood as Type 2 endless war driven by the pursuit of an unlimited and unachievable objective that was stated very clearly.

For most of the counter-ISIS war, the United States clearly and publicly explained its objective. For example, on September 10, 2014, Obama described the objective in the counter-ISIS war, saying: “Our objective is clear: We will degrade, and ultimately destroy, ISIL through a comprehensive and sustained counterterrorism strategy.”³¹

In contrast, the counterterrorism war in Yemen was born in secrecy. The United States denied it was even waging a war. Once the United States acknowledged it was waging a war in Yemen, it did not provide a specific explanation of the objective in the way that Obama did as he initiated the war against ISIS. Instead, the United States alternated between a range of objectives.

In the counter-ISIS war, the unlimited objective of destroying ISIS has proven unachievable. The United States destroyed ISIS’s territorial expression in Syria and Iraq (best understood as a limited but transformative objective of denying ISIS territory), but the group continues to operate.³²

In contrast, the United States often embraced limited objectives in its counterterrorism war in Yemen, including killing specific AQAP operatives and disrupting external attack plotting. The United States at times, has contended that it is not pursuing a larger military campaign to transform governance in Yemen or destroy AQAP. Many of the limited objectives in Yemen were, at least theoretically, achievable. Some, like killing Anwar Awlaki, were achieved. Yet the United States also maintained a broader and unstable definition of what else it was pursuing, including an unlimited objective of destroying AQAP.

The distinction between the two wars’ objectives is not a bright line. As the United States finds itself stuck in Syria and Iraq unable to fully destroy ISIS as a movement or group, the counter-ISIS war may be moving towards a confused jumble of re-defined objectives that may be more limited but that are not as clearly stated.³³ This is a shift from a Type 2 endless war to a Type 1 or 3 endless war, depending on the extent to which “defeat” remains an objective. In essence, it has come to look more like the war in Yemen.

Regarding the level of threat, the counter-ISIS war and the war in Yemen also had important similarities. Neither ISIS nor AQAP held the capability to defeat the United States or deny it military access to the battlefield. Thus, both wars held the potential for endlessness, assuming the United States did not carefully define achievable objectives.

However, unlike ISIS, whose threat to the homeland was very low and framed in terms of preventive war logic, AQAP demonstrated an existing capability to directly attack the United States. The strategic context of U.S. choices—in terms of homeland security—was thus starker than it was during the initiation of the war against ISIS.

In both wars the United States also showed a low level of preparation and planning for war termination. In the counter-ISIS war, the United States eventually developed effective partnerships with the Iraqi government and the largely Kurdish Syrian Democratic Forces (SDF) while mitigating many of the technical challenges of these partnerships.³⁴ Yet these mitigation strategies often relied on close U.S. involvement. In particular, the United States has struggled to develop a clear vision of how the SDF will fit into Syrian politics in the absence of a protective U.S. shield.³⁵

In Yemen, the United States has had little success managing tensions with and among its partners, saw its Yemeni-government partner collapse, and today relies largely upon the Saudis and Emiratis, whose efforts face substantial limitations. In both wars, the United States demonstrated only limited efforts and capability to resolve underlying systemic socio-economic crises that hold the potential to fuel resurgences in the threat to U.S. interests that could shift policymaker and public perceptions and motivate a return to war.

It is important to identify the roots of the Yemen war’s endlessness because it involves more than just the adoption of expansive objectives. In addition to abandoning the mirage of destroying AQAP, the United States will also need to clarify its limited objectives and improve war termination planning processes. Restraint-oriented policymakers should take heed that only embracing parts of this agenda could merely shift the war in Yemen into a different type of endlessness.