A Thought Experiment: You walk into your home to find an armed intruder threatening to shoot your spouse and children, trapped with nowhere to run. Fortunately, you have a gun.

You try to negotiate, but the intruder is in no mood to talk. His intention is murder.

You have seconds to decide. What do you do?

For many, the answer is clear. You fight to save your family. And most of us would call that self defense. Most Christians would agree that any action would be not only morally permissible, but also morally required.

Now imagine another scenario: You are a CIA interrogator facing an avowed terrorist who was caught in the act of preparing for murder. You know he has information about a plot to blow up an unidentified building in a large American city. Innocent lives hang in the balance.

For hours you have attempted to extract the life-saving information from him, but to no avail. The last option is one you believe will work: water-boarding, but you have only a few minutes to decide. What do you do?

Again, for most of us, the answer is clear. You do what you have to do to save those innocent lives, which in this case means water-boarding the terrorist. You are saving other people's families.

In the continuing debate over the morality of enhanced interrogation, an essential consideration is often overlooked: intent. For Christians, intent is integral to determining whether and when certain techniques, including water-boarding, are morally permissible.

Historically, various forms of harsh interrogation have been employed as a means to punish, humiliate, intimidate, exact revenge or force a confession. Consider Cuba, where for half a century torture has been used to punish, humiliate and intimidate those who speak out against the ruling Marxist regime and for democratic values and basic human rights.

In an interview for this piece, Cuban Eleno Oviedo recalled the torture he experienced as a political prisoner of 26 years in Castro's prisons. "I was stripped in a cell and left in solitary confinement for the first 126 days," he said about the time after his initial abduction. The regime's intention, Oviedo said, was to get him to confess to being a CIA agent. Oviedo, who now lives in the United States, said that other political prisoners were left naked for weeks at a time. Some prisoners' fingers were cut or had their fingernails torn off. Others received beatings so severe that they died. And "three-hundred times I heard prisoners being executed" by firing squad, Oviedo recalled. And the torture continues. The horrors of Castro's gulag make us recoil in disgust, and their intentions and methods of torture should be rejected by a just society.

However, the issue which has been ignored to date in the discussion of enhanced interrogation is whether there is a difference between inflicting pain for its own sake or using some harsher methods with deliberation when lives are on the line. When the intent is to extract information necessary to save human beings in imminent danger, harsh treatment may be justified and, I believe, sometimes necessary.

Just War Theory offers criteria for Christians to consider when determining under what circumstances enhanced interrogations may be justified. With roots in Greek and Roman philosophy, Just War Theory was given a Christian formulation in the Fourth Century when St. Augustine applied biblical principles to this very human question: When is war justified?

The Christian Just War Doctrine derives from a need to reconcile various Bible passages. Jesus tells us to "turn the other cheek" (Matt: 5:39), but he also told the apostles "let him who has no sword sell his mantel and buy one" (Luke 22:36). Also, in the Old Testament's book of Ecclesiastes we are told that there is "a time to kill."

Under Just War Theory, a war is just only if it is defensive and meets four strict conditions. The requirements are: that the damage inflicted by the aggressor must be lasting, grave and certain; that there must be serious prospects of success; that all other means of ending the war must be shown to be impractical or ineffective; and that the use of force cannot produce evils graver than those to be eliminated.

Applying the first of the criterion to the water-boarding debate, we can better analyze the proverbial ticking time-bomb scenario. It is an extreme example, but it is not as rare as some suggest. Israeli authorities say they have thwarted dozens of imminent terrorist attacks saving countless civilian lives. These successes with water-boarding and other enhanced interrogation also help fulfill the second requirement of just war, that there must be serious prospects of success. The CIA's water-boarding of al Qaeda leader Khalid Sheik Mohammed (KSM) compelled him to reveal information that allowed the U.S. government to thwart a planned attack on Los Angeles. CIA officials have stated that they would not have been able to obtain critical information to prevent attacks without the use of enhanced interrogation including water-boarding. They had tried other means and failed.

Reports recently released by the Justice Department state that information elicited from KSM "dramatically expanded our universe of knowledge of Al Qaeda's plots." Former CIA director George Tenet has said, "From our interrogation of KSM and other senior al Qaeda members . . . we learned many things. For example, more than 20 plots had been put in motion by al Qaeda against U.S. infrastructure targets, including communications nodes, nuclear power plants, dams, bridges and tunnels."

The third criterion is that all other means of ending the war must be impractical or ineffective. CIA memos revealed that less harsh interrogation was always used before water-boarding was employed. Methods used included stress positions, loud music and confinement in small spaces, but those tools were not enough.

The fourth criterion might be the most difficult to meet. It is that the use of force cannot produce evils greater than those to be eliminated. In the case of Mohammad, innocent lives were saved as a consequence of the information received by interrogation officials after water boarding, which, as agonizing as it can be, leaves no long-term physical effects on the prisoners. In fact, some of our own soldiers are water-boarded as part of their training.

It is vital in times like these to have a vigorous debate about how best to defend our nation. Christians especially are troubled by the reality that "the heart is deceitfully wicked, and who can know it?" We need to let the light of public debate shine into the darkness of the dangers we are confronting and of the temptations in the hearts of men and women to go too far against an enemy committed to our destruction.

Enhanced interrogation is not to be considered lightly, but the use of enhanced interrogation techniques does not require moral people to abandon their beliefs. Rather, it is precisely during these difficult times that one's beliefs about life, justice and mercy become indispensible. Just War Theory applied to the thorny issue of torture acknowledges the dignity of all human life and the abhorrence of torture. But it also creates a set of conditions that, if met, justify the use of force to save innocent lives facing imminent death.