In the aftermath of the United States military response to the car-bombing of American embassies in Kenya and Tanzania last August, New York’s John Cardinal O’Connor drew a distinction between ad hoc, after-the-fact moral judgments about such particular responses to terrorism and a serious national effort to add a moral dimension to policy and military planning for future efforts against terrorist activities. “I would hope,” wrote Cardinal O’Connor, “that if our government has not yet done so, it would appeal to scholars of the moral dimensions of warfare to offer their analyses of what we seem to be about as a nation” in responding to terrorism.

There is significant precedent for doing this. From the mid-1980s to the early 1990s, in response to the terror bombing of the Marine barracks in Beirut and the growth of terrorist threats to Americans at home and abroad, the U.S. military made a series of efforts to bring moral philosophers and theologians into dialogue with the military officers and civilians involved in policy planning or holding command responsibility. The Naval War College and the Army War College took the lead in this, each providing the venue for various events aiming at such dialogue. Over time the focus shifted to a broader context, culminating in a conference on legal and moral constraints on low-intensity conflict held at the Naval War College in 1992 and the publication of a book in an NWC-sponsored series three years later. The dialogue carried on in this way has, however, not been continued since.

We need to renew these conversations. In dealing with terrorism and with international affairs in general, the seven years from 1992 to the present is a long time. Policies go out of date; personnel charged with interpreting and implementing them change; the shape of military readiness alters; the sources and nature of terrorist threats shift. Indeed, while Cardinal O’Connor is right to call special attention to the need for the government to initiate such a dialogue, the discussion should be broadened to include the American people as a whole. In a democracy such as ours, informed public support is a necessity for any effective policy. It is especially important to have such support for action against terrorists, because of the moral complexity and public nature of terrorism and counter terrorism.

No doubt some Americans are inclined to say that in the war against terrorism, anything goes. Understandable as this is when Americans, Kenyans, and Tanzanians are blown apart by car bombs, it is not the attitude Americans should take toward the struggle against terrorism. Such an attitude is in fact the mirror image of Osama bin Laden’s declaration, contrary to the normative traditions of Islam, that all Americans are equally worthy to be targeted in his putative holy war against the U.S. A judgment that “anything goes” in dealing with him and other terrorists would equally violate our society’s own normative traditions.

Like Cardinal O’Connor, I would argue that the reference point for thinking morally about responses to terrorism should be the just war tradition. This tradition is the collective record of Western culture’s attempt to think morally about the use of military force in the service of an orderly, just, and peaceful world, and its influence can be seen broadly in recent debate. The issue is how this tradition is relevant to the problem of responding to terrorist activities.

For a war to be just, Thomas Aquinas argued, three things are necessary: sovereign authority, just cause, and right intention. Even today these concerns remain central. The requirement of sovereign authority in Thomas and throughout just war thought speaks to two issues. First, it means that the resort to force must be undertaken as a public act, on behalf of a political community that has been wronged in some serious way. Second, it means that there is no superior authority to which a wronged party can appeal to receive justice and settle a dispute. One can find these considerations behind the right under contemporary international law to use force in self-defense against armed attack. Put simply, any country targeted by terrorist acts is justified in a military response, both morally and by the terms of international law.

But Thomas also brought into focus a specific concern of his own time, one raised today by the phenomenon of terrorism: the obligation of every sovereign authority to curb and punish lawless people who strike at the order, justice, and peace that are the core purpose of political community. Terrorism by its nature aims to undermine and erode these goods and thus attacks all people who benefit from them. While the tradition has allowed for the possibility of a war between two states both seeming, because of the complexity of the issues involved, to be just, the kind of violence we today call terrorism is evil in its very nature, because it attacks the foundations of political community itself. The authority to use force to curb and punish terrorism is thus the same authority that seeks to protect the goods of the political order as such. There is no justice in terrorism, only injustice.

In just war terms, there is just cause when force is used to defend against attack, to retake something wrongly taken, or to punish evil. Much recent moral thought has focused on only one of these, the use of force in defense. Contemporary international law also has restricted the allowable use of force to self-defense, but in response to the realities of international order the customary behavior of states has effectively expanded the idea of defense to include the other traditional justifications. It is not necessary when thinking morally (or legally) about the use of force in counter terrorism to restrict such force to after-the-fact response to particular violent acts; nor is it necessary to deal with terrorist activities on a tit-for-tat basis, though the use of force would be justified in such cases. Let me be clear: a strategy that involves the use of military force to prevent terrorist acts is just and moral. Right intention , in historical just war theory, had both a negative and a positive meaning. Negatively it meant the avoidance of the desire to bully or dominate, to take something for one’s own benefit, to inflict harm out of hatred or what Augustine called “implacable animosity.” While the moral requirement of right intention cautions U.S. policymakers not to fashion uses of force against terrorism that amount to riding roughshod over other states and peoples, it also draws attention to the fact that frequently terrorist self-justifications give evidence of a fundamental hatred for all that is American”an “implacable animosity.”

Positively, the just war requirement of right intention historically meant that use of military force should aim at restoring or creating a just peace. Contemporary theorists typically count peace separately, rather than folding it into right intention. However this concept is conceived theoretically, it is fundamental to the formation of moral policy in thinking about how to deal with terrorism, whether by military or other means. One problem with ad hoc, after-the-fact, tit-for-tat reactions to particular terrorist acts is that in themselves they look backwards to those acts, not forward to the establishment of a just and well-ordered peace in which terrorism no longer threatens. How to conceive and bring about such a peace is, indeed, the greatest challenge for a policy against terrorism.

Thinking about terrorism in just war terms requires taking certain prudential concerns into account: Is the good accomplished proportional to the means used? Are there any other means of dealing with the problem that have a reasonable prospect of succeeding? Is there a reasonable hope of success? Both historically and logically, these concerns are secondary to those termed “necessary”; yet they are nonetheless important additional guidelines for moral policy and decisions regarding potential uses of force. In particular, these prudential criteria remind us that the use of military force is neither the preferred nor the only option for dealing with terrorism. As awesome a weapon as the cruise missile is, for example, its availability does not diminish the importance of other weapons in the struggle against terrorism: policies aimed at cutting off terrorist capabilities, removing their support, eliminating conditions in which they tend to flourish, gathering and sharing intelligence about individual terrorists and terrorist organizations, and bringing them to justice. A moral policy on dealing with terrorism should incorporate such approaches along with the possibility of resort to military force.

Justified force, if used, should directly and intentionally target only the guilty, and the means used should be such as to avoid harm to others so far as possible. Michael Walzer has it right, I believe, in arguing that the moral principles governing the use of force imply a special care to protect innocent parties from “collateral damage” due to force aimed at the guilty. Since it is a preferred tactic of terrorists to shelter themselves among innocent people and to use the fabric of normal life as a cover for their own activities, this is a particular problem for any policy against terrorism, and it may be the hardest to resolve. For”as Walzer makes plain”the effort to avoid harm to the innocent may require taking more potential danger onto oneself. The most moral military approach against terrorists may require risking the lives of American military personnel and accepting the losses that may come of this. This is not to argue that counter terrorist policy should focus on commando raids and larger military expeditions in preference to cruise missile strikes; rather, it is to say that a morally adequate policy for dealing with terrorism cannot be limited only to the relatively easy options.

The actual contours of moral debate over policy on dealing with the ongoing problem of terrorism remain to be determined. Like Cardinal O’Connor, I believe we should carry on that debate with the purpose of shaping policy that is adequate morally as well as politically and militarily. Moral reflection is not doing its job when it is employed only in retrospect, in response to particular terrorist acts.

James Turner Johnson is Professor of Religion at Rutgers University.