The editors of the "On Faith" blog of the Washington Post/ Newsweek asked their panel of religious teachers, of whom I am one, this question:

What should we call terrorists, some of whom claim to be motivated by their religion? Can one be an Islamic terrorist? What about a Christian terrorist? Does what we call terrorists matter?

My answer follows:

First, we should be clear that sometimes the name "terrorism" is attached by media and the public to actions that are not, and sometimes it is not attached to actions that are.

By US and other official military definitions, terrorism means attacks on civilians intended to terrorize a civilian population into a different political stance.

Sometimes attacks on civilians are carried out by official states with uniformed armies, sometimes under the cover of claims that attacks on civilians were accidental or unintended. But in my opinion as a rabbi, a Jew, and a human being, when continued experience (as in US drone attacks that keep killing Afghan or Pakistani civilians) shows that such attacks DO regularly and repeatedly kill civilians, we should name such attacks "state terrorism."

But this honesty would disturb the comfort of conventional media and citizens of such states. Instead, the label "terrorist" is mostly attached only to "non-state actors" without flags or UN memberships.

It may be useful in assessing the sociology of various terrorist groups to refer to some who claim religious authority for their acts by naming their alleged religious connection, BUT it is crucial to make clear that these references do not affirm these claims. How accomplish both ends? Not by calling them 'Christian terrorists' or 'Muslim terrorists,' etc. Instead --

On condition that we are clear about the claims of all terrorists, not just Muslims, about their justification, it might make sense to note:

For Al Qaeda etc, and SOME within Hamas and Hezbollah, "Terrorists who falsely claim justification in Islam"

For the KKK, some of the IRA, "pro-life" anti-abortion murderers, and the murderer who bombed the Federal building in Oklahoma, "Terrorists who falsely claim justification in Christianity"
For Baruch/ Aror Goldstein (the murderer of 29 Muslims prostrate in prayer at the mosque of the Tomb of Abraham), and various assorted Israeli settlers on the West Bank who have violently attacked Palestinians and their crops -- not all settlers -- "Terrorists who falsely claim justification in Judaism."

For the Sikhs who assassinated Indira Gandhi (in "retaliation" for her attack on the Golden Temple, which of course was a "retaliation" for their -- etc etc etc --- "Terrorists who falsely claim justification in Sikhism."

For some of the Buddhists of Sri Lanka who have raped and killed civilian members of the Tamil minority there, "Terrorists who falsely claim justification in Buddhism,"
Etc.
It is not surprising that -- given the majority ethos in American culture, identifying Christianity and perhaps Judaism as good and homey while Islam is identified as alien at best and evil at worst -- American usage has allowed the description of some terrorists as "Muslim terrorists," but has failed to call IRA killers or those who have killed abortion providers "Christian terrorists."

Not surprising, but not acceptable. Either all terrorists who claim religious reasons should have that identity named, or none. If the former, it should be made explicit in official and unofficial statements that their self-justification on religious grounds is false in the eyes of most authorities in their own religious tradition. (Otherwise, identifying them as "Christian or "Muslim" or "Jewish" terrorists could easily be taken to affirm their actions as legitimate Christian or Muslim or Jewish practice.)

More important, we should be noticing that terrorists tend to sprout because they think -- often but not always correctly -- that their community is being ruthlessly oppressed, and that more formal weaponry and the military targeting available to their oppressors is not available to them. They may justify their choice of terrorist acts in religious terms, but almost always it is the despairing sense of "oppression forever" that matters.

THAT is what should be the major concern of those who want to prevent terrorism: taking great care to assess whether there is real oppression of their identity-group, and if so making sure that the oppression ends.

If the claim of oppression seems untrue – for example, the claim of some Israeli settlers on the West Bank to represent resistance to present-day oppression of the Jewish people seems quite out of touch with present-day reality – then attention should be paid to the shaping of that mind-set.

In that specific case, the long long history of oppression of the Jews, culminating in the Holocaust and reinforced by violence from some Palestinian and other Arab groups, would need to be addressed.

If in that and perhaps similar cases the problem is a kind of collective cultural "post-traumatic stress syndrome," then all involved should be trying to heal it rather than justifying terrorism by citing the trauma.

So it may be important as part of social diagnosis to note and name the claim of religious justification by particular terrorists, but much more important to address the claim of oppression.