Q. You know that recently the U.S. forces have started bombing the terrorists in Iraq, to prevent a genocide, to protect minorities, including Catholics who are under your guidance. My question is this: do you approve the American bombing?
A. Thanks for such a clear question. In these cases where there is an unjust aggression, I can only say this: it is licit to stop the unjust aggressor. I underline the verb: stop. I do not say bomb, make war, I say stop by some means. With what means can they be stopped? These have to be evaluated. To stop the unjust aggressor is licit.
But we must also have memory. How many times under this excuse of stopping an unjust aggressor the powers [that intervened] have taken control of peoples, and have made a true war of conquest.
One nation alone cannot judge how to stop an unjust aggressor. After the Second World War there was the idea of the United Nations. It is there that this should be discussed. Is there an unjust aggressor? It would seem there is. How do we stop him? Only that, nothing more.
Secondly, you mentioned the minorities. Thanks for that word because they talk to me about the Christians, the poor Christians. It’s true, they suffer. The martyrs, there are many martyrs. But here there are men and women, religious minorities, not all of them Christian, and they are all equal before God.
To stop the unjust aggressor is a right that humanity has, but it is also a right that the aggressor has to be stopped so that he does not do evil. Source here