From a deontological view, argue for torturing terrorists in order to obtain information from them.
Since deontological arguments are arguments that proceed from moral rules, there are many ways to make this argument. Let us look at a possible Kantian argument for such torture.
Kant argues that an action is moral if we can will that the rule behind our action would become a universal law. Therefore, we must come up with an acceptable universal law that would justify torturing terrorists. We might say something like "it is acceptable to torture people who are proven to be terrorists when, by doing so, we have a very good chance of saving other people's lives.
It is not at all clear that Kant would agree with this given that torture would likely be a way of treating another person as a means and not an end, but this is the sort of deontological argument that could justify torture.