Similarly with the Just War theology. There was a time when the Church did not scruple to go to war. Julius II in his papal helmet surmounted by three concentric tiaras climbing over the walls of Bologna! And the Crusades—all of them—not just the ones in the Holy Land but the crusades in the Balkans and in the Baltic, against the Turks and against the Albigensians. What is the problem? Well today we scruple a bit about war. People get hurt. It isn’t nice. And so we find a more restricted theory on what makes a war “just.”
So what are we to think of the assassination of Osama Bin Laden.
Let’s look first at Evangelium Vitae, paragraph 55:
This should not cause surprise: to kill a human being, in whom the image of God is present, is a particularly serious sin. Only God is the master of life! Yet from the beginning, faced with the many and often tragic cases which occur in the life of individuals and society, Christian reflection has sought a fuller and deeper understanding of what God's commandment prohibits and prescribes. There are in fact situations in which values proposed by God's Law seem to involve a genuine paradox. This happens for example in the case of legitimate defence, in which the right to protect one's own life and the duty not to harm someone else's life are difficult to reconcile in practice. Certainly, the intrinsic value of life and the duty to love oneself no less than others are the basis of a true right to self-defence. The demanding commandment of love of neighbour, set forth in the Old Testament and confirmed by Jesus, itself presupposes love of oneself as the basis of comparison: "You shall love your neighbour as yourself " (Mk 12:31). Consequently, no one can renounce the right to self-defence out of lack of love for life or for self. This can only be done in virtue of a heroic love which deepens and transfigures the love of self into a radical self-offering, according to the spirit of the Gospel Beatitudes (cf. Mt 5:38-40). The sublime example of this self-offering is the Lord Jesus himself.
Moreover, "legitimate defence can be not only a right but a grave duty for someone responsible for another's life, the common good of the family or of the State". Unfortunately it happens that the need to render the aggressor incapable of causing harm sometimes involves taking his life. In this case, the fatal outcome is attributable to the aggressor whose action brought it about, even though he may not be morally responsible because of a lack of the use of reason.
It would seem from Evangelium Vitae that the assassination of Osama Bin Laden is, according to Catholic teaching, one of the few legitimate instances of a direct taking of human life. This warrant for the killing of Obama is not the same as the death penalty which the Church sees as almost never a moral option and which has been specifically condemned by both Popes John Paul II and Benedict XVI for how it is used in the United States, a situation in which non-lethal means are sufficient to defend and protect people’s safety. What makes the assassination of Bin Ladin different from the death penalty is that it is not an execution after a judicial process, but an extra-judicial decision to take a life in order to protect the lives of others. Let’s hope it works.
And then there is article 2267 of the Catechism of the Catholic ChurchAssuming that the guilty party's identity and responsibility have been fully determined, the traditional teaching of the Church does not exclude recourse to the death penalty, if this is the only possible way of effectively defending human lives against the unjust aggressor.
If, however, non-lethal means are sufficient to defend and protect people's safety from the aggressor, authority will limit itself to such means, as these are more in keeping with the concrete conditions of the common good and more in conformity to the dignity of the human person.
Today, in fact, as a consequence of the possibilities which the state has for effectively preventing crime, by rendering one who has committed an offense incapable of doing harm - without definitely taking away from him the possibility of redeeming himself - the cases in which the execution of the offender is an absolute necessity "are very rare, if not practically nonexistent."