Rules are wonderful. … Yet rules have limitations, too, and we should be careful about specifying and applying rules where they do not work.

Rules are wonderful. They simplify decision-making by providing us with clear guidelines for making choices within a particular context. Anyone who has driven a car in an environment in which the rules of the road are either badly specified or poorly observed knows that it is both stressful and frightening. Yet rules have limitations, too, and we should be careful about specifying and applying rules where they do not work.

America’s difficult experiences in Afghanistan and Iraq, the rise of ISIS, and the discussion surrounding American intervention in Syria, have seen a resurgence in interest in articulating (or defending) good rules for the use of the military. Such efforts are most pronounced in the aftermath of unsuccessful U.S. military adventures. For years, American policy-makers and national security experts have argued about guidelines to govern the use of military force. Perhaps the most well-known examples of rule-based approaches are the Weinberger doctrine and Colin Powell’s modification of it (though Powell was careful not to use the word “rules”). Several months ago, the Cato Institute’s Dr. Christopher Preble, published an article titled “New Rules for U.S. Military Intervention.” This takes its place in that long tradition of attempting to define rules for the use of military force. An analysis of Preble’s rules is useful for considering both the wisdom of the rules themselves and the broader question of whether it makes sense for the U.S. to specify such rules at all.

Vital Interests

Preble’s first rule: “The United States should not send U.S. troops into harm’s way unless a vital U.S. national security interest is at stake.”

To paraphrase an old aphorism, “One man’s vital interest is another man’s peripheral interest.” What is vital? Preble anticipates this problem, defining vital interests very narrowly, as the physical security of the nation and safety of its citizenry. This approach has several critical problems.

First, eliminating our allies’ vital interests as rationale for U.S. military intervention, as advocated in his article, calls into question each of our standing collective defense arrangements and the corresponding security and stability provided by those treaties.

Second, Preble indicates that economic prosperity is an “important goal” but falls outside the criteria of being a vital interest. As economics underlies all instruments of national power, it is difficult to understand how important economic interests are insufficient to justify the use of the military.

Third, one of the best uses of the military is to start to manage and control a situation before Americans come under physical threat. When America declared war on Japan in December 1941, Germany (weirdly, given its treachery in other security agreements) honored its Axis agreement with Japan and declared war on the U.S. However, let us imagine for a moment that Germany had not done so. Would U.S. intervention in the European war have been justified? Not under Preble’s definition of vital interests. Preble essentially precludes the use of military force in preventing or deterring a more serious threat.

The conventional U.S. military is a powerful deterrent, below the threshold of nuclear weapons. Deterrence requires proportionality and credibility, which are provided through a trained and ready force, and the will to use it.

Preble offers this rule as a distinctly more “stringent” criterion than that of the corresponding point from Secretary Weinberger’s famous doctrine. Ironically, the Weinberger Doctrine, and the modified version from General Colin Powell, were already too stringent to be of true utility during the policy assessment process. This was splendidly highlighted by Secretary of State Madeleine Albright when she demanded of General Powell in a discussion about the Balkans, “What’s the point of having this superb military that you’re always talking about if we can’t use it?”

President Clinton’s 2000 National Security Strategy defined important interests as those that “affect our national well-being or that of the world in which we live.” It is hard to imagine a future administration not assessing the potential use of force on behalf of an important U.S. interest.

Clear National Consensus

Preble’s second rule: “The American people must understand why they are being asked to risk blood and treasure and, crucially, they must have a say in whether to do so.”

The historical record does not support this rule as a useful guide for policy. Since World War II, the U.S. has entered a major military commitment without broad public support only once, in Korea in 1950. The public overwhelmingly supported sending troops to Vietnam in 1965, the Afghan military intervention in 2001 and the invasion of Iraq in 2003. Thus, one of America’s most successful military interventions of the post-WWII era breaks the rule, while its most frustrating conflicts (Vietnam, Afghanistan, and Iraq), do not.

The desire for consensus support of a military intervention is common across the guidelines of Secretary Weinberger, General Powell, and Dr. Preble. Of course it would be nice to have a national consensus prior to the country embarking on an overseas military adventure. Yet the public is fickle. Patriotic fervor is often high at the start of a war, and abates once the true character of the conflict reveals itself. It is more prudent to think in terms of a reasonable assurance of support if an intervention goes badly.

Understanding the Costs of War

Preble’s third rule: “We must also understand the costs of war and know how we will pay them.”

Given Preble’s first rule, this one seems unnecessary. If only a vital interest will necessitate deploying combat forces, then cost is not an object, due to the immediate, physical nature of the threat.

Nevertheless, let us consider costs. It is frankly impossible to predict accurately any war’s duration or cost. This is not only due to a lack of prescience amongst policymakers, but also the complex nature of politics and the uncertainty of warfare. The U.S. goes to war when it considers the value of the object is worth the anticipated cost at the start of the conflict. It is idiotic to do otherwise.

A better guideline is to assess value of the object of a war relative to a range of possible outcomes.  The key question is not whether we know all the costs at the start (we do not), but whether the object remains valuable enough if our initial cost estimates are wildly inaccurate. If, for example, the war is twice as expensive in blood, money, and time, do we still consider it worthwhile? At what level of cost would we choose not to go to war? Logically, we should also have a plan to pay for a war (in both money and force development) should our worst-case estimates prove accurate.

Clear and Obtainable Military Objectives

Preble’s fourth rule: “The U.S. military should never be sent into harm’s way without a set of clear and obtainable military objectives.”

Do national leaders really need to be told that they should not commit military forces without clear and obtainable objectives? One of my professors at the Army War College was fond of mocking what he called “be handsome” advice, which he described as counsel that is simultaneously completely obvious in theory and hard to follow in practice. This rule is definitely “be handsome” advice.

‘Military intervention’ is not a binary construct. Simplistic interpretations of the Weinberger Doctrine, the Powell Doctrine, and the “New Rules for U.S. Military Intervention” all hinge on a false dilemma concerning the employment of military force.

Ex ante, leaders can try to be clear about military objectives, but the obtainability of those objectives is hard to know in advance. The difficulty in achieving the objectives of the U.S. intervention in Vietnam, or the invasions of Afghanistan and Iraq was not recognized beforehand. Certainly, policy makers could have been smarter. They ignored experts who tried to alert them to the difficulties of the undertaking. However, at the start of a war, it is useful to ask ourselves not just whether our military objectives can be obtained, but what assumptions must be true for us to obtain them, and how confident we should be in those assumptions.

Force as a Last Resort

Preble’s final rule: “Force should be used only as a last resort.”

The intent behind this point is sound – we should always hesitate before going to war. This rule echoes the Weinberger Doctrine, and is expressed with a question in the Powell Doctrine, “Have all other non-violent policy means been fully exhausted?” However, as in those cases, it is unrealistic to formalize this as a rule.

It is empirically impossible to know when force is a last resort. We will never know for certain that no other option is possible. The term “last resort” means that all alternative approaches have been tried (or at least considered) and found wanting. Yet there can always be another round of sanctions, further diplomacy, or a third-party intervention to consider. “Options” are themselves a social construction – we collectively decide what an option is, and we can create new options all the time. During the Cuban Missile Crisis, President Kennedy’s determination to avoid armed conflict with the Soviets led to a dynamic evolution of options throughout the crisis.

War is costly and uncertain, and should be undertaken cautiously and only when we feel very confident that we cannot achieve our objectives another way. Such confidence, when justified, is the result of a variety of factors, including sound political judgment, an understanding of history, and an effective decision-making process that values dissent.

The Trouble with Rules

The bigger question is whether rules for intervention are even useful. I think they are not, for three reasons. First, “military intervention” is not a binary construct. Simplistic interpretations of the Weinberger Doctrine, the Powell Doctrine, and the “New Rules for U.S. Military Intervention” all hinge on a false dilemma concerning the employment of military force. Yet “military intervention” is a vague term. The options are never total war or no war. An intervention can feature ground, naval or air forces, as well as a panoply of alternatives that span the continuum of conflict, including intervention and employment choices such as foreign internal defense, security force assistance, military information support operations, civil affairs operations, and advise and assist operations. All expose Americans to potential harm, however, the risks vary considerably.

Second, war is competitive, and other players pay attention to what we say and do. When the U.S. clearly articulates rules for intervention, it affects the behavior of potential adversaries. When we send clear signal that the U.S. will not intervene due to a strict threshold, we cede strategic space for adversaries to maneuver. This affects U.S. interests globally.

Third, rules for intervention wish away the important work that happens both before and (especially) after the decision to intervene militarily. We like the six rules posed by the Secretary of Defense in 1984 – they provide a comforting sense of direction. Nostalgia for the Weinberger Doctrine stems from a frustration with wars that have not ended cleanly in Iraq and Afghanistan. It is as if the Weinberger/Powell doctrine is the reason for success in the 1991 Gulf War, and a failure to observe it was the reason for failure in other recent wars. We condense success or failure in war down to a question of whether to initial decision to fight was the right one. This is an appealing story, but it is also wrong. Perhaps the invasion of Iraq was an error, yet we (the U.S. military) compounded policy errors through bad subsequent choices, and better military choices might have improved the apparent quality of what we now see as bad policy. Military execution matters, and the conditions and objectives of wars change.

Ironically, both Secretary Weinberger and General Powell seem to have understood these nuances. The six rules of the Weinberger Doctrine were encapsulated in a nearly 4,000 word speech full of nuance, and a thoughtful discussion of the conditions and caveats that accompany the difficult deliberations involved in using the military. For his part, General Powell warned us against an overly simplistic approach in decision-making. In Foreign Affairs he wrote, “There is, however, no fixed set of rules for the use of military force. To set one up is dangerous.” General Powell cites both the risk to deterrence and the need for a thorough evaluation of the circumstances at hand. Such an evaluation cannot be achieved through a simple checklist.  It is therefore ironic how often the “Powell Doctrine” is invoked as a clear, concise evaluation tool.

Military intervention is not black and white. Ignoring the complexities of such a decision by distilling it down to an under-informed checklist is folly.



Mark Kappelmann is a colonel in the U.S. Army and a graduate of the U.S. Army War College resident class of 2017. The views in this article are those of the author and do not necessarily represent those of the U.S. Army or the U.S. Government.

Photo: A U.S. Army AH-64A Apache Attack Helicopter From Task Force Hawk Comes in for a Landing At Rinas Airport In Tirana, Albania on April 21, 1999.

Photo Credit:  USAF/Getty Images

Print Friendly, PDF & Email

Join the Conversation

1 Comment

  1. Colonel Kappelmann:

    Within the context of Israeli-Palestinian peace talks, in December 2000, then President Clinton formulated several parameters for peace later elevated to the status of the “Clinton Parameters.” Clinton’s first two parameters of Territory and Security could be applied to the grave discussion of “rules for intervention.”

    Historically, battles over territories as small as Kuwait or a large as France or Czechoslovakia could be cited as reasons to go to war. The parameter of Security is less tangible, but no less compelling. Security concerns after the bombing and destruction of the World Trade Center in 2001 caused a majority of the members of Congress to authorize the Global War on Terror, which was later renamed to Overseas Contingency Operations. Security concerns after the “surprise” bombing of Pearl Harbor in 1941 launched our young nation onto the global stage with complex territorial concerns as well as safety-at-sea fears and frustrations.

    Perhaps a third modern day parameter of Humanity could be added to the Clinton calculus. Ruanda, the Balkans provided, and more recently Syria still provides, arguments for and against launching or responding to armed conflict. The horrors of the Holocaust were not immediately evident to all World War II decision makers, but in retrospect the terrible toll of 6 million lives lost to satisfy blind bigotry provides an indelible lesson learned. No rules should ever dictate going to war or prevent nations from launching a just war, but Territory, Security, and Humanity seem to be time-worn parameters for the powers that be to balance the equations of today and tomorrow (as we remember out-of-balance events of yesteryear).

Leave a comment

Your email address will not be published. Required fields are marked *