Now I've gone over all of this before but perhaps we can utilize some other examples from history to make this a bit more poignant.
In the late 2nd Century BC the Jugurthine War broke out in North Africa leading Rome to intervene. As far as Rome was concerned this uprising, this rejection of the Roman geopolitical paradigm, constituted a threat to Rome's interest and thus they sent an army to deal with Jugurtha.
There were Jews living in Italy during the late Roman Republic. What was the Jewish response to Jugurtha? What was the response of the Old Covenant Diaspora? Certainly our situation in the New Testament is analogous. We too live in an empire. What were their 'worldview' teachers saying about what the 'Jewish' response should be... for Rome to deal with Jugurtha?
The Church doesn't think of itself in these terms. American Christians do not think of themselves as a Diaspora, a pilgrim people. Do you suppose the Jews put Roman banners in their synagogues and sang songs praising Rome? They knew that Rome represented the same kind of violence the rebels in North Africa threatened. It wasn't good Rome or Rome the saviour. It was evil vs. evil.
Maybe stable evil is better than chaotic evil, but it's still evil.
What about in the 3rd century? Christians lived in pagan Rome and pagan Persia. At this time Zenobia rose up and temporarily seceded from Rome creating the empire of Palmyra. This was indeed a serious threat to Rome's geopolitical might and standing as well as an economic threat.
To put it into today's terms the Zenobian uprising represented an existential threat to Rome. They had to respond.
But what was the Christian response?
Again, it's kind of a silly question. The Christians living in Rome or in Syria didn't really view it as a Christian issue. Of course Rome would respond and a great deal of blood would be shed. The Church didn't endorse that even if it was understood that it would happen.
Repent and lay down your weapons!
Peacefully dismantle the Roman Empire!
Not likely. But that should still be our message. I'm not saying it's always easy or uncomplicated. Of course there were Christians living under Zenobia. She didn't present a problem for them and yet I'm sure they resented the fact that it brought legions and war into the region.
All war is to be resented and avoided. We can never endorse the violence and those that try and argue it's an act of love have completely distorted the message of the Kingdom and aren't operating in reality.
These arguments which exist both in Roman and Protestant circles float in the ideological ether. Their definitions and how they're dealing with the concepts do not represent reality. As I wrote recently this is a common problem when it comes to the academy.
War is murder and death. There's nothing loving or glorious about it. There are times when people are almost forced to wage it but more often than not men have contributed to the situation and created the conditions that lead to unnecessary and thus always immoral bloodshed.
And then we write history books to justify and rationalize our deeds. In other words we craft a mythology that fits our narrative.
Geopolitics is complicated as is the interpretation of history. The teaching of the New Testament concerning violence is pretty straightforward. The confusion and difficulty arises as a result of the Constantinian Shift. At this point the church was infused with a whole new set of ideas and paradigms which effectively cast down the original New Testament model and the ways of thinking that dominated the Early Church.
It was an abominable catastrophe and we're still reaping the harvest. The Church has invested itself politically. It created doctrines to accommodate the new reality and subsequently built doctrines on top of those doctrines. This has complicated the situation and the thinking of the average person sitting in the pew.
The Shift meant the Church has a stake in the game and thus has continually comprised its prophetic voice and it has (ironically) secularised the Kingdom. Rather than building a Kingdom that you must have eyes to see and a born again heart to grasp, it has redefined the Kingdom in terms of the state and the culture.
The state as Romans 13 teaches us is a tool of Providence, but it is ultimately little more than violence. Contrasted with the non-vengeful non-violent believers in the previous chapter, it serves a purpose but doesn't build the Kingdom, and contrary to the assertions of many in our day does not survive This Age. It is categorically 'not' part of the Redemptive Kingdom work of the Holy Spirit and will most certainly perish in the fire as will all the works of men.
ISIS is an abomination created by years of violence and bloodshed... instigated by the British and more recently the American Empire. Destroying it with violence will only beget more violence. I expect that's what the United States will continue to do.