My question is this: in a situation of aggression or violence directed towards the citizenry, are clergy of any rank prohibited from using force to defend themselves or their people?
Historically, the Eastern Churches have prohibited the clergy from carrying weapons or spilling blood, and those who did were usually returned to the lay state. Anna Comnena, in the Alexiad, writes of the scandal caused by Frankish monks and priests riding in the Crusader army wearing full panoply of armor and carrying maces. Apparently in the West the injunction against carrying a sword was taken very literally, so that Bishop Odo of Bayeux, half-brother of William the Bastard (aka the Conqueror) fought in the Battle of Hastings wielding a wicked looking club (he's featured prominently in the Bayeux Tapestry, which he commissioned).
In the East, while clerics did not bear arms, they played an active role in the defense of their people, as spiritual and sometimes as military commanders. During several of the sieges of Constantinople, the Archbishop of the time helped rally the defenders and maintained morale by delivering exhortatory sermons, leading prayer services, and carrying icons around the walls of the city.
St. Sergei of Radonezh played a similar role in the defeat of the Golden Horde, by advising and blessing Dmitry Donskoi prior to the Battle of Kulikov.
Now,
in extremis, it's pretty clear that an Eastern cleric
can use force (even lethal force) to defend the innocent (self-defense is not so clear cut), but if he does, then canonically he would have to be laicized, the injunction against spilling blood being so deeply embedded in the Tradition.
Unfortunately, there are plenty of instances, mainly in the genocidal wars of the Balkans, of Orthodox clerics actually participating not merely in combat, but in atrocities against others. They were not alone in this--it's a bad neighborhood, and Catholic and Muslim clergy did the same thing. That is one reason why I think the ideal should be upheld to the greatest extent possible.
