Recently, Major Tony Pfaff, a member of the Army's JAG Corps, published an essay in which he highlighted the difference between actions involving law enforcement and those involving military combat. This has long been an issue of confusion among Americans and the international community.

In law enforcement, a crime is committed. Law enforcement officials go to the scene, ascertain that a transgression occurred, and then ask: "Who did it?" The criminal is then sought, brought before a judge, charged with the crime, submitted to a judicial hearing, and the case adjudicated.

In combat, people are captured during the course of military operations. They are removed from the battlespace, and taken to a place of detention. Then their captors attempt to ascertain who they are and what they have done, in order to determine whether they should be punished or released.

The use of force and the danger -- not to the perpetrators, but to uninvolved bystanders -- are strikingly different.

Pfaff writes: "To the police, the threat is a criminal they must apprehend in order to minimize the disruption to the peace that crime represents. Since the use of violence represents a further disruption of the peace, police are always looking to use the least force possible. But Marines and soldiers are trained to defeat enemies, who must be killed if there is to be peace. They are always looking to use the most force permissible."

The problem arises, of course, in complex contingencies like Iraq, when it is not entirely clear whether the law-enforcement or the combat model applies, and decisions must be made rapidly and correctly or lives will be lost.

Yet, this serves only as a beginning to understanding the difficulties and the complexities that attend modern warfare, about which so much confusion reigns. Today, the United States is asking, and the international community is expecting, that U.S. military forces:

-- deploy somewhere they have never been;

-- engage in combat an adversary they have never fought;

-- use weapons and equipment that have never been used in combat, sometimes in ways that were never intended;

-- carry out their orders regardless of weather or visibility;

-- continue to perform in the horrific presence of death or grisly wounding of friends as well as adversaries;

-- operate on the basis of incomplete, untimely, and perhaps incorrect information;

-- pursue sometimes vague, conflicting, or incomprehensible objectives;

-- conduct combat operations under the unblinking eye of the television camera, and the constant scrutiny of the media;

-- tolerate long separations from family and loved ones;

-- endure limited public support, and sometimes open hostility, from the home front;

-- absorb minimum casualties from an adversary that might fight in unconventional, unanticipated, or illegitimate ways; and

-- achieve their objectives (i.e. win) quickly while inflicting minimum casualties on the adversary; causing minimal destruction to property and the environment and minimal casualties to non-combatants; providing assistance to injured combatants and non-combatants, and being prepared to restore that which has been damaged; triggering in the process no malign unintended consequences.

They are expected to do all this under a body of military doctrine, rules of engagement, and international law formulated in and for a radically different context.

Thus, one witnesses in a recent conflict an armed force imbedded in a sovereign state (Hezbollah in Lebanon) placing missiles to be fired against another sovereign state (Israel) in the homes of civilians. Then when conflict is sparked by an incursion into Israel and the kidnapping of Israeli soldiers, Hezbollah -- not in uniform, not carrying weapons openly -- integrates with the Lebanese civilian (noncombatant) community.

The effect is deliberately to maximize noncombatant casualties on both sides: in Lebanon, by Israeli attacks on the hiding places for the missiles and on Hezbollah fighters integrated with the civilian populace; and in Israel, by the indiscriminately launched missiles. Within the Geneva Conventions, which have as their centerpiece the protection of noncombatants in time of armed conflict, "grave breaches" are spelled out clearly, and these are as grave as one can imagine.

Yet, there was no international outrage against Hezbollah, no effort to capture Hezbollah fighters or leaders and "bring them to justice." Instead, Israel is criticized for a disproportionate response and Hezbollah is given a pass.

International law is clearly incapable of coping with situations where the law is exploited in order to create an advantage for the lawbreakers. In like manner, current international law cannot bring those responsible for genocide in Africa before the bar. Nor can it possibly find the means to cope with those who subsidize child soldiers or reward the families of suicidal terrorists. Neither can it deal with unwitting car bomb volunteers, the latest wrinkle in Iraq, where a carjacking occurs and during the process a wireless-activated bomb is attached. The car and driver are then released and remotely detonated later, at a place where casualties can be maximized.

The antiquated systems of doctrine, international law, and rules of engagement currently tilt the environment to the adversary's advantage. My book Asymmetrical Warfare sets forth this thesis in detail, and argues that these systems and rules must change or, in the long run, we will forfeit our freedom.

Roger W. Barnett is a retired Navy captain professor emeritus of the Naval War College.