In this situation, what can we do and what ought we to do? Let us begin by noting some basic truths. It is impossible to overcome terrorism, illegal violence detached from morality, by force alone. It is indeed true that the defense of the rule of law against those who seek to destroy it must sometimes employ violence. This element of force must be precisely calculated, and its goal must always be the protection of the law. An absolute pacifism that refused to grant the law any effective means for its enforcement would be a capitulation to injustice. It would sanction the seizure of power by this injustice and would surrender the world to the dictatorship of force; we reflected briefly on this at the beginning of this essay. But in order for force to be employed by law and not itself become unjust, it must submit to strict criteria that are recognizable by all. It must pay heed to the causes of terrorism, which often has it sources in injustices against which no effective action is taken. This is why the system of law must endeavor to use all available means to clear up any situations of injustice. Above all, it is important to contribute a measure of forgiveness, in order to break the cycle of violence. Where the principle of “an eye for an eye” is applied without pity, it is impossible to escape the power of that cycle. Gestures of a humanity that breaks through it by seeking the human person in one’s foe and appealing to his humanity are necessary, even where they seem at first glance to be a waste of time.
–Joseph Cardinal Ratzinger (Pope Benedict XVI), “Searching for Peace: Tensions and Dangers” in Values in a Time of Upheaval. Trans. Brian McNeil (San Francisco: Ignatius Press, 2006), 106-107.